Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder
characterised by excessive amounts of
Attention is the behavioral and cognitive process of selectively concentrating on a discrete aspect of information, whether considered subjective or objective, while ignoring other perceivable information. William James (1890) wrote that "At ...
, hyperactivity, and
In psychology, impulsivity (or impulsiveness) is a tendency to act on a whim, displaying behavior characterized by little or no forethought, reflection, or consideration of the consequences. Impulsive actions are typically "poorly conceived, pre ...
that are pervasive, impairing in multiple contexts, and otherwise age-inappropriate
ADHD symptoms arise from executive dysfunction
and emotional dysregulation
is often considered a core symptom.
In children, problems paying attention may result in poor school performance
. ADHD is associated with other neurodevelopmental and
A mental disorder, also referred to as a mental illness or psychiatric disorder, is a behavioral or mental pattern that causes significant distress or impairment of personal functioning. Such features may be persistent, relapsing and remitt ...
s as well as some non-psychiatric disorders, which can cause additional impairment, especially in modern society. Although people with ADHD struggle to focus on tasks they are not particularly interested in completing, they are often able to maintain an unusually prolonged and intense level of attention for tasks they do find interesting or rewarding; this is known as hyperfocus
The precise causes of ADHD are unknown in the majority of cases.
[ Genetic factors play an important role; ADHD tends to run in families and has a heritability rate of 74%. Toxins and infections during pregnancy and brain damage may be environmental risks.
It affects about 5–7% of children when diagnosed via the ] DSM-IV
The ''Diagnostic and Statistical Manual of Mental Disorders'' (DSM; latest edition: DSM-5-TR, published in March 2022) is a publication by the American Psychiatric Association (APA) for the classification of mental disorders using a common langua ... criteria, and 1–2% when diagnosed via the ICD-10
ICD-10 is the 10th revision of the International Statistical Classification of Diseases and Related Health Problems (ICD), a medical classification list by the World Health Organization (WHO). It contains codes for diseases, signs and symptoms, ... criteria. Rates are similar between countries and differences in rates depend mostly on how it is diagnosed. ADHD is diagnosed approximately twice as often in boys than in girls, [ and 1.6 times more often in men than in women,] [ although the disorder is overlooked in girls or diagnosed in later life because their symptoms sometimes differ from diagnostic criteria.] About 30–50% of people diagnosed in childhood continue to have ADHD in adulthood, with 2.58% of adults estimated to have ADHD which began in childhood. In adults, hyperactivity is usually replaced by inner restlessness, and adults often develop coping
Coping refers to conscious strategies used to reduce unpleasant emotions. Coping strategies can be cognitions or behaviours and can be individual or social.
Theories of coping
Hundreds of coping strategies have been proposed in an attempt to ... skills to compensate for their impairments. The condition can be difficult to tell apart from other conditions, as well as from high levels of activity within the range of normal behavior. ADHD has a negative impact on patients’ health related quality of life and that this may be further exacerbated by, or may increase the risk of, other psychiatric conditions such as anxiety and depression. [ Text was copied from this source, which is available under ]
ADHD management recommendations vary and usually involve some combination of medications,
Creative Commons Attribution 4.0 International License
Counseling is the professional guidance of the individual by utilizing psychological methods especially in collecting case history data, using various techniques of the personal interview, and testing interests and aptitudes.
This is a list of co ..., and lifestyle changes. The British guideline emphasises environmental modifications and education for individuals and carers about ADHD as the first response. If symptoms persist, parent-training, medication, or psychotherapy (especially cognitive behavioral therapy
Cognitive behavioral therapy (CBT) is a psycho-social intervention that aims to reduce symptoms of various mental health conditions, primarily depression and anxiety disorders. CBT focuses on challenging and changing cognitive distortions (su ...) can be recommended based on age. Canadian and American guidelines recommend medications and behavioral therapy together, except in preschool-aged children for whom the first-line treatment is behavioral therapy alone. Stimulant medications are the most effective pharmaceutical treatment, although there may be side effects and any improvements will be reverted if medication is ceased.
ADHD, its diagnosis, and its treatment have been considered controversial since the 1970s. These controversies have involved doctors, teachers, policymakers, parents, and the media. Topics have included causes of ADHD and the use of stimulant medications in its treatment. ADHD is now a well-validated clinical diagnosis in children and adults, and the debate in the scientific community mainly centers on how it is diagnosed and treated. ADHD was officially known as attention deficit disorder (ADD) from 1980 to 1987; prior to the 1980s, it was known as hyperkinetic reaction of childhood. Symptoms similar to those of ADHD have been described in medical literature dating back to the 18th century.
Signs and symptoms
Inattention, hyperactivity (restlessness in adults), disruptive behavior, and impulsivity are common in ADHD.
[ Academic difficulties are frequent as are problems with relationships.] [ The symptoms can be difficult to define, as it is hard to draw a line at where normal levels of inattention, hyperactivity, and impulsivity end and significant levels requiring interventions begin.]
According to the fifth edition of the ''Diagnostic and Statistical Manual of Mental Disorders'' (DSM-5) and its text revision ( DSM-5-TR
The ''Diagnostic and Statistical Manual of Mental Disorders'' (DSM; latest edition: DSM-5-TR, published in March 2022) is a publication by the American Psychiatric Association (APA) for the classification of mental disorders using a common langua ...), symptoms must be present for six months or more to a degree that is much greater than others of the same age. [ This requires at least six symptoms of either inattention or hyperactivity/impulsivity for those under 17 and at least five symptoms for those 17 years or older.] [ The symptoms must be present in at least two settings (e.g., social, school, work, or home), and must directly interfere with or reduce quality of functioning.] [ Additionally, several symptoms must have been present before age twelve.] [
ADHD is divided into three primary presentations:
* predominantly inattentive (ADHD-PI or ADHD-I)
* predominantly hyperactive-impulsive (ADHD-PH or ADHD-HI)
* combined type (ADHD-C).
The table "Symptoms" lists the symptoms for ADHD-I and ADHD-HI from two major classification systems. Symptoms which can be better explained by another psychiatric or medical condition which an individual has are not considered to be a symptom of ADHD for that person.
Girls and women with ADHD tend to display fewer hyperactivity and impulsivity symptoms but more symptoms of inattention and distractibility.
Symptoms are expressed differently and more subtly as the individual ages. Hyperactivity tends to become less overt with age and turns into inner restlessness, difficulty relaxing or remaining still, talkativeness or constant mental activity in teens and adults with ADHD. Impulsivity in adulthood may appear as thoughtless behaviour, impatience, irresponsible spending and sensation-seeking behaviours, while inattention may appear as becoming easily bored, difficulty with organization, remaining on task and making decisions, and sensitivity to stress.
Although not listed as an official symptom for this condition, emotional dysregulation or mood lability is generally understood to be a common symptom of ADHD. People with ADHD of all ages are more likely to have problems with social skills
A social skill is any competence facilitating interaction and communication with others where social rules and relations are created, communicated, and changed in verbal and nonverbal ways. The process of learning these skills is called soci ..., such as social interaction and forming and maintaining friendships. This is true for all presentations. About half of children and adolescents with ADHD experience social rejection by their peers compared to 10–15% of non-ADHD children and adolescents. People with attention deficits are prone to having difficulty processing verbal and nonverbal language which can negatively affect social interaction. They also may drift off during conversations, miss social cues, and have trouble learning social skills.
Difficulties managing anger are more common in children with ADHD as are delays in speech, language and motor development. Poorer handwriting
Handwriting is the writing done with a writing instrument, such as a pen or pencil, in the hand. Handwriting includes both printing and cursive styles and is separate from formal calligraphy or typeface. Because each person's handwriting is u ... is more common in children with ADHD. Poor handwriting in many situations can be a side effect of ADHD in itself due to decreased attentiveness but when it's a constant problem it may also be in part due to both Dyslexic
Dyslexia, also known until the 1960s as word blindness, is a disorder characterized by reading below the expected level for one's age. Different people are affected to different degrees. Problems may include difficulties in spelling words, r ... and Dysgraphic individuals having higher rates of ADHD than the general population, with 3 in 10 people who have dyslexia also having ADHD. Although it causes significant difficulty, many children with ADHD have an attention span equal to or greater than that of other children for tasks and subjects they find interesting.
In children, ADHD occurs with other disorders about two-thirds of the time.
Other neurodevelopmental conditions are common comorbidities. Autism spectrum disorder
The autism spectrum, often referred to as just autism or in the context of a professional diagnosis autism spectrum disorder (ASD) or autism spectrum condition (ASC), is a neurodevelopmental condition (or conditions) characterized by difficulti ... (ASD), co-occurring at a rate of 21% in those with ADHD, affects social skills, ability to communicate, behaviour, and interests. Both ADHD and ASD can be diagnosed in the same person. [ ] Learning disabilities
Learning disability, learning disorder, or learning difficulty (British English) is a condition in the brain that causes difficulties comprehending or processing information and can be caused by several different factors. Given the "difficult ... have been found to occur in about 20–30% of children with ADHD. Learning disabilities can include developmental speech and language disorders, and academic skills disorders. ADHD, however, is not considered a learning disability, but it very frequently causes academic difficulties. Intellectual disabilities
Intellectual disability (ID), also known as general learning disability in the United Kingdom and formerly mental retardation, Rosa's Law, Pub. L. 111-256124 Stat. 2643(2010). is a generalized neurodevelopmental disorder characterized by signifi ... [ and Tourette's syndrome] are also common.
ADHD is often comorbid with disruptive, impulse control, and conduct disorders. Oppositional defiant disorder (ODD) occurs in about 25% of children with an inattentive presentation and 50% of those with a combined presentation. [ It is characterised by angry or irritable mood, argumentative or defiant behavior and vindictiveness which are age-inappropriate. Conduct disorder (CD) occurs in about 25% of adolescents with ADHD.] [ It is characterised by aggression, destruction of property, deceitfulness, theft and violations of rules.] Adolescents with ADHD who also have CD are more likely to develop antisocial personality disorder
Antisocial personality disorder (ASPD or infrequently APD) is a personality disorder characterized by a long-term pattern of disregard of, or violation of, the rights of others as well as a difficulty sustaining long-term relationships. Lack ... in adulthood. Brain imaging supports that CD and ADHD are separate conditions, wherein conduct disorder was shown to reduce the size of one's temporal lobe and limbic system
The limbic system, also known as the paleomammalian cortex, is a set of brain structures located on both sides of the thalamus, immediately beneath the medial temporal lobe of the cerebrum primarily in the forebrain.Schacter, Daniel L. 2012. ''Ps ..., and increase the size of one's orbitofrontal cortex
The orbitofrontal cortex (OFC) is a prefrontal cortex region in the frontal lobes of the brain which is involved in the cognitive process of decision-making. In non-human primates it consists of the association cortex areas Brodmann area 11, 1 ..., whereas ADHD was shown to reduce connections in the cerebellum
The cerebellum (Latin for "little brain") is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as or even larger. In humans, the cere ... and prefrontal cortex more broadly. Conduct disorder involves more impairment in motivation control than ADHD. Intermittent explosive disorder is characterised by sudden and disproportionate outbursts of anger and co-occurs in individuals with ADHD more frequently than in the general population. [
Anxiety and mood disorders are frequent comorbidities. ] Anxiety disorder
Anxiety disorders are a cluster of mental disorders characterized by significant and uncontrollable feelings of anxiety and fear such that a person's social, occupational, and personal function are significantly impaired. Anxiety may cause physi ...s have been found to occur more commonly in the ADHD population, as have mood disorder
A mood disorder, also known as an affective disorder, is any of a group of conditions of mental and behavioral disorder where a disturbance in the person's mood is the main underlying feature. The classification is in the ''Diagnostic and Stat ...s (especially bipolar disorder
Bipolar disorder, previously known as manic depression, is a mental disorder characterized by periods of depression and periods of abnormally elevated mood that last from days to weeks each. If the elevated mood is severe or associated with ... and major depressive disorder
Major depressive disorder (MDD), also known as clinical depression, is a mental disorder characterized by at least two weeks of pervasive low mood, low self-esteem, and loss of interest or pleasure in normally enjoyable activities. Introd ...). Boys diagnosed with the combined ADHD subtype are more likely to have a mood disorder. Adults and children with ADHD sometimes also have bipolar disorder, which requires careful assessment to accurately diagnose and treat both conditions.
A sleep disorder, or somnipathy, is a medical disorder of an individual's sleep patterns. Some sleep disorders are severe enough to interfere with normal physical, mental, social and emotional functioning. Polysomnography and actigraphy are tes ... and ADHD commonly co-exist. They can also occur as a side effect of medications used to treat ADHD. In children with ADHD, insomnia
Insomnia, also known as sleeplessness, is a sleep disorder in which people have trouble sleeping. They may have difficulty falling asleep, or staying asleep as long as desired. Insomnia is typically followed by daytime sleepiness, low energy, ... is the most common sleep disorder with behavioral therapy being the preferred treatment. Problems with sleep initiation are common among individuals with ADHD but often they will be deep sleepers and have significant difficulty getting up in the morning. Melatonin
Melatonin is a natural product found in plants and animals. It is primarily known in animals as a hormone released by the pineal gland in the brain at night, and has long been associated with control of the sleep–wake cycle.
In vertebrates ... is sometimes used in children who have sleep onset insomnia. Specifically, the sleep disorder restless legs syndrome
Restless legs syndrome (RLS), also known as Willis-Ekbom disease (WED), is generally a long-term disorder that causes a strong urge to move one's legs. There is often an unpleasant feeling in the legs that improves somewhat by moving them. This ... has been found to be more common in those with ADHD and is often due to iron deficiency anemia
Iron-deficiency anemia is anemia caused by a lack of iron. Anemia is defined as a decrease in the number of red blood cells or the amount of hemoglobin in the blood. When onset is slow, symptoms are often vague such as feeling tired, weak, shor .... However, restless legs can simply be a part of ADHD and requires careful assessment to differentiate between the two disorders. Delayed sleep phase disorder
Delayed sleep phase disorder (DSPD), more often known as delayed sleep phase syndrome and also as delayed sleep–wake phase disorder, is a delaying of a person's circadian rhythm (biological clock) compared to those of societal norms. The diso ... is also a common comorbidity of those with ADHD.
There are other psychiatric conditions which are often co-morbid with ADHD, such as substance use disorder
Substance use disorder (SUD) is the persistent use of drugs (including alcohol) despite substantial harm and adverse consequences as a result of their use. Substance use disorders are characterized by an array of mental/emotional, physical, and b ...s. Individuals with ADHD are at increased risk of substance abuse
Substance abuse, also known as drug abuse, is the use of a drug in amounts or by methods which are harmful to the individual or others. It is a form of substance-related disorder. Differing definitions of drug abuse are used in public health, .... This is most commonly seen with alcohol or cannabis
''Cannabis'' () is a genus of flowering plants in the family Cannabaceae. The number of species within the genus is disputed. Three species may be recognized: ''Cannabis sativa'', '' C. indica'', and '' C. ruderalis''. Alternatively .... The reason for this may be an altered reward pathway in the brains of ADHD individuals, self-treatment and increased psychosocial risk factors. This makes the evaluation and treatment of ADHD more difficult, with serious substance misuse problems usually treated first due to their greater risks. Other psychiatric conditions include reactive attachment disorder
Reactive attachment disorder (RAD) is described in clinical literature as a severe and relatively uncommon disorder that can affect children, although these issues do occasionally persist into adulthood.DSM-IV-TR (2000) American Psychiatric As ..., characterised by a severe inability to appropriately relate socially, and sluggish cognitive tempo, a cluster of symptoms that potentially comprises another attention disorder and may occur in 30–50% of ADHD cases, regardless of the subtype. Individuals with ADHD are 4x more likely to develop and be diagnosed with an eating disorder (Anorexia, Bulimia, Binge Eating, ARFID) compared to those without ADHD. Individuals with diagnosed eating disorders are 2.6x more likely to have ADHD than those without eating disorders, though these numbers are likely much lower than actual rates, due to limitations with screening and diagnosis in marginalized populations.
ADHD, trauma, and Adverse Childhood Experiences are also comorbid,
which could in part be potentially explained by the similarity in presentation between different diagnoses. The symptoms of ADHD and PTSD
Post-traumatic stress disorder (PTSD) is a mental and behavioral disorder that can develop because of exposure to a traumatic event, such as sexual assault, warfare, traffic collisions, child abuse, domestic violence, or other threats on ... can have significant behavioral overlap with ADHD—in particular, motor restlessness, difficulty concentrating, distractibility, irritability/anger, emotional constriction or dysregulation, poor impulse control, and forgetfulness are common in both. This could result in trauma-related disorders or ADHD being mis-identified as the other. Additionally, traumatic events in childhood are a risk factor for ADHD - it can lead to structural brain changes and the development of ADHD behaviors. Finally, the behavioral consequences of ADHD symptoms cause a higher chance of the individual experiencing trauma (and therefore ADHD leads to a concrete diagnosis of a trauma-related disorder).
Some non-psychiatric conditions are also comorbidities of ADHD. This includes
Epilepsy is a group of non-communicable neurological disorders characterized by recurrent epileptic seizures. Epileptic seizures can vary from brief and nearly undetectable periods to long periods of vigorous shaking due to abnormal electrical ..., a neurological condition characterised by recurrent seizures. There are well established associations between ADHD and obesity, asthma
Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, co ... and sleep disorders, and an association with celiac disease. Children with ADHD have a higher risk for migraine
Migraine (, ) is a common neurological disorder characterized by recurrent headaches. Typically, the associated headache affects one side of the head, is pulsating in nature, may be moderate to severe in intensity, and could last from a few ho ... headaches, but have no increased risk of tension-type headaches. In addition, children with ADHD may also experience headaches as a result of medication.
A 2021 review reported that several neurometabolic disorders caused by inborn errors of metabolism converge on common neurochemical mechanisms that interfere with biological mechanisms also considered central in ADHD pathophysiology and treatment. This highlights the importance of close collaboration between health services to avoid clinical overshadowing.
Systematic reviews conducted in 2017 and 2020 found strong evidence that ADHD is associated with increased
Suicide is the act of intentionally causing one's own death. Mental disorders (including depression, bipolar disorder, schizophrenia, personality disorders, anxiety disorders), physical disorders (such as chronic fatigue syndrome), and ... risk across all age groups, as well as growing evidence that an ADHD diagnosis in childhood or adolescence represents a significant future suicidal risk factor. Potential causes include ADHD's association with functional impairment, negative social, educational and occupational outcomes, and financial distress. A 2019 meta-analysis indicated a significant association between ADHD and suicidal spectrum behaviors (suicidal attempts, ideations, plans, and completed suicides); across the studies examined, the prevalence of suicide attempts in individuals with ADHD was 18.9%, compared to 9.3% in individuals without ADHD, and the findings were substantially replicated among studies which adjusted for other variables. However, the relationship between ADHD and suicidal spectrum behaviors remains unclear due to mixed findings across individual studies and the complicating impact of comorbid psychiatric disorders. There is no clear data on whether there is a direct relationship between ADHD and suicidality, or whether ADHD increases suicide risk through comorbidities.
IQ test performance
Certain studies have found that people with ADHD tend to have lower scores on intelligence quotient (IQ) tests.
The significance of this is controversial due to the differences between people with ADHD and the difficulty determining the influence of symptoms, such as distractibility, on lower scores rather than intellectual capacity. In studies of ADHD, higher IQs may be over-represented because many studies exclude individuals who have lower IQs despite those with ADHD scoring on average nine points lower on standardized intelligence measures. In individuals with high intelligence, there is increased risk of a missed ADHD diagnosis, possibly because of compensatory strategies in highly intelligent individuals.
Studies of adults suggest that negative differences in intelligence are not meaningful and may be explained by associated health problems.
ADHD is generally claimed to be the result of neurological dysfunction in processes associated with the production or use of
Dopamine (DA, a contraction of 3,4-dihydroxyphenethylamine) is a neuromodulatory molecule that plays several important roles in cells. It is an organic chemical of the catecholamine and phenethylamine families. Dopamine constitutes about 8 ... and norepinephrine
Norepinephrine (NE), also called noradrenaline (NA) or noradrenalin, is an organic chemical in the catecholamine family that functions in the brain and body as both a hormone and neurotransmitter. The name "noradrenaline" (from Latin '' ad'' ... in various brain structures, but there are no confirmed causes. It may involve interactions between genetics and the environment.
ADHD has a high
Heritability is a statistic used in the fields of breeding and genetics that estimates the degree of ''variation'' in a phenotypic trait in a population that is due to genetic variation between individuals in that population. The concept of heri ... of 74%, meaning that 74% of the presence of ADHD in the population is due to genetic factors. There are multiple gene variants which each slightly increase the likelihood of a person having ADHD; it is polygenic
A polygene is a member of a group of non-epistatic genes that interact additively to influence a phenotypic trait, thus contributing to multiple-gene inheritance (polygenic inheritance, multigenic inheritance, quantitative inheritance), a type of ... and arises through the combination of many gene variants which each have a small effect. The siblings of children with ADHD are three to four times more likely to develop the disorder than siblings of children without the disorder.
Arousal is related to dopaminergic functioning, and ADHD presents with low dopaminergic functioning. Typically, a number of genes are involved, many of which directly affect dopamine neurotransmission. Those involved with dopamine include DAT, DRD4, DRD5
Dopamine receptor D5, also known as D1BR, is a protein that in humans is encoded by the ''DRD5'' gene. It belongs to the D1-like receptor family along with the D1 receptor subtype.
D5 receptor is a subtype of the dopamine recepto ..., TAAR1
Trace amine-associated receptor 1 (TAAR1) is a trace amine-associated receptor (TAAR) protein that in humans is encoded by the ''TAAR1'' gene. TAAR1 is an intracellular amine-activated and G protein-coupled receptor (GPCR) that is primarily e ..., MAOA, COMT
Catechol-''O''-methyltransferase (COMT; ) is one of several enzymes that degrade catecholamines (neurotransmitters such as dopamine, epinephrine, and norepinephrine), catecholestrogens, and various drugs and substances having a catechol structu ..., and DBH. Other genes associated with ADHD include SERT, HTR1B, SNAP25
Synaptosomal-Associated Protein, 25kDa (SNAP-25) is a Target Soluble NSF (''N''-ethylmaleimide-sensitive factor) Attachment Protein Receptor (t-SNARE) protein encoded by the ''SNAP25'' gene found on chromosome 20p12.2 in humans. SNAP-25 is a comp ..., GRIN2A, ADRA2A, TPH2, and BDNF
Brain-derived neurotrophic factor (BDNF), or abrineurin, is a protein found in the and the periphery. that, in humans, is encoded by the ''BDNF'' gene. BDNF is a member of the neurotrophin family of growth factors, which are related to the cano .... A common variant of a gene called latrophilin 3 is estimated to be responsible for about 9% of cases and when this variant is present, people are particularly responsive to stimulant medication. The 7 repeat variant of dopamine receptor D4 (DRD4–7R) causes increased inhibitory effects induced by dopamine
Dopamine (DA, a contraction of 3,4-dihydroxyphenethylamine) is a neuromodulatory molecule that plays several important roles in cells. It is an organic chemical of the catecholamine and phenethylamine families. Dopamine constitutes about 8 ... and is associated with ADHD. The DRD4 receptor is a G protein-coupled receptor
G protein-coupled receptors (GPCRs), also known as seven-(pass)-transmembrane domain receptors, 7TM receptors, heptahelical receptors, serpentine receptors, and G protein-linked receptors (GPLR), form a large group of evolutionarily-related p ... that inhibits adenylyl cyclase
Adenylate cyclase (EC 126.96.36.199, also commonly known as adenyl cyclase and adenylyl cyclase, abbreviated AC) is an enzyme with systematic name ATP diphosphate-lyase (cyclizing; 3′,5′-cyclic-AMP-forming). It catalyzes the following reaction:
:A .... The DRD4–7R mutation results in a wide range of behavioral phenotype
In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological pr ...s, including ADHD symptoms reflecting split attention. The DRD4 gene is both linked to novelty seeking and ADHD. The genes GFOD1 and CDH13 show strong genetic associations with ADHD. CHD13's association with ASD, schizophrenia
Schizophrenia is a mental disorder characterized by continuous or relapsing episodes of psychosis. Major symptoms include hallucinations (typically hearing voices), delusions, and disorganized thinking. Other symptoms include social wit ..., bipolar disorder, and depression make it an interesting candidate causative gene. Another candidate causative gene that has been identified is ADGRL3. In zebrafish, knockout of this gene causes a loss of dopaminergic function in the ventral diencephalon
The diencephalon (or interbrain) is a division of the forebrain (embryonic ''prosencephalon''). It is situated between the telencephalon and the midbrain (embryonic ''mesencephalon''). The diencephalon has also been known as the 'tweenbrain in o ... and the fish display a hyperactive/impulsive phenotype
In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological pr ....
For genetic variation to be used as a tool for diagnosis, more validating studies need to be performed. However, smaller studies have shown that genetic polymorphism
A gene is said to be polymorphic if more than one allele occupies that gene's locus within a population. In addition to having more than one allele at a specific locus, each allele must also occur in the population at a rate of at least 1% to ge ...s in genes related to catecholaminergic
Catecholaminergic means "related to catecholamines". The catecholamine neurotransmitters include dopamine, epinephrine (adrenaline), and norepinephrine (noradrenaline).
A catecholaminergic agent (or drug) is a chemical which functions to directly ... neurotransmission or the SNARE complex of the synapse
In the nervous system, a synapse is a structure that permits a neuron (or nerve cell) to pass an electrical or chemical signal to another neuron or to the target effector cell.
Synapses are essential to the transmission of nervous impulses fro ... can reliably predict a person's response to stimulant medication. Rare genetic variants show more relevant clinical significance as their penetrance (the chance of developing the disorder) tends to be much higher. However their usefulness as tools for diagnosis is limited as no single gene predicts ADHD. ASD shows genetic overlap with ADHD at both common and rare levels of genetic variation.
In addition to genetics, some environmental factors might play a role in causing ADHD.
Alcohol intake during pregnancy can cause fetal alcohol spectrum disorders which can include ADHD or symptoms like it. Children exposed to certain toxic substances, such as lead
Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly c ... or polychlorinated biphenyls
Polychlorinated biphenyls (PCBs) are highly carcinogenic chemical compounds, formerly used in industrial and consumer products, whose production was banned in the United States by the Toxic Substances Control Act in 1979 and internationally by ..., may develop problems which resemble ADHD. Exposure to the organophosphate
In organic chemistry, organophosphates (also known as phosphate esters, or OPEs) are a class of organophosphorus compounds with the general structure , a central phosphate molecule with alkyl or aromatic substituents. They can be considered a ... insecticides chlorpyrifos
Chlorpyrifos (CPS), also known as Chlorpyrifos ethyl, is an organophosphate pesticide that has been used on crops, animals, and buildings, and in other settings, to kill several pests, including insects and worms. It acts on the nervous systems ... and dialkyl phosphate is associated with an increased risk; however, the evidence is not conclusive. Exposure to tobacco smoke during pregnancy can cause problems with central nervous system development and can increase the risk of ADHD. Nicotine
Nicotine is a naturally produced alkaloid in the nightshade family of plants (most predominantly in tobacco and '' Duboisia hopwoodii'') and is widely used recreationally as a stimulant and anxiolytic. As a pharmaceutical drug, it is used for ... exposure during pregnancy may be an environmental risk.
Extreme premature birth
Preterm birth, also known as premature birth, is the birth of a baby at fewer than 37 weeks gestational age, as opposed to full-term delivery at approximately 40 weeks. Extreme preterm is less than 28 weeks, very early preterm birth is between ..., very low birth weight, and extreme neglect, abuse, or social deprivation also increase the risk as do certain infections during pregnancy, at birth, and in early childhood. These infections include, among others, various viruses ( measles
Measles is a highly contagious infectious disease caused by measles virus. Symptoms usually develop 10–12 days after exposure to an infected person and last 7–10 days. Initial symptoms typically include fever, often greater than , coug ..., varicella zoster encephalitis, rubella
Rubella, also known as German measles or three-day measles, is an infection caused by the rubella virus. This disease is often mild, with half of people not realizing that they are infected. A rash may start around two weeks after exposure and ..., enterovirus 71
Enterovirus 71 (EV71), also known as Enterovirus A71 (EV-A71), is a virus of the genus '' Enterovirus'' in the ''Picornaviridae'' family, notable for its role in causing epidemics of severe neurological disease and hand, foot, and mouth disease i ...). At least 30% of children with a traumatic brain injury
A traumatic brain injury (TBI), also known as an intracranial injury, is an injury to the brain caused by an external force. TBI can be classified based on severity (ranging from mild traumatic brain injury TBI/concussionto severe traumatic b ... later develop ADHD and about 5% of cases are due to brain damage.
Some studies suggest that in a small number of children, artificial food dye
Food coloring, or color additive, is any dye, pigment, or substance that imparts color when it is added to food or drink. They come in many forms consisting of liquids, powders, gels, and pastes. Food coloring is used in both commercial food ...s or preservatives
A preservative is a substance or a chemical that is added to products such as food products, beverages, pharmaceutical drugs, paints, biological samples, cosmetics, wood, and many other products to prevent decomposition by microbial growth or by ... may be associated with an increased prevalence of ADHD or ADHD-like symptoms, but the evidence is weak and may only apply to children with food sensitivities. The European Union
The European Union (EU) is a supranational union, supranational political union, political and economic union of Member state of the European Union, member states that are located primarily in Europe, Europe. The union has a total area of ... has put in place regulatory measures based on these concerns. In a minority of children, intolerances or allergies
Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic derma ... to certain foods may worsen ADHD symptoms.
Individuals with hypokalemic sensory overstimulation are sometimes diagnosed as having attention deficit hyperactivity disorder (ADHD), raising the possibility that a subtype of ADHD has a cause that can be understood mechanistically and treated in a novel way. The sensory overload is treatable with oral potassium gluconate
Potassium gluconate is the potassium salt of the conjugate base of gluconic acid. It is also referred to as 2,3,4,5,6-pentahydroxycaproic acid potassium salt, D-gluconic acid potassium salt, or potassium D-gluconate.
It contains 16.69% potassium ....
Research does not support popular beliefs that ADHD is caused by eating too much refined sugar, watching too much television, parenting, poverty or family chaos; however, they might worsen ADHD symptoms in certain people.
The youngest children in a class have been found to be more likely to be diagnosed as having ADHD, possibly due to them being developmentally behind their older classmates. They also appear to use ADHD medications at nearly twice the rate of their peers.
In some cases, an inappropriate diagnosis of ADHD may reflect a
A dysfunctional family is a family in which conflict, misbehavior, and often child neglect or abuse and sometimes even all of the above on the part of individual parents occur continuously and regularly, leading other members to accommodate such ... or a poor educational system
The educational system generally refers to the structure of all institutions and the opportunities for obtaining education within a country. It includes all pre-school institutions, starting from family education, and/or early childhood education ..., rather than any true presence of ADHD in the individual. In other cases, it may be explained by increasing academic expectations, with a diagnosis being a method for parents in some countries to get extra financial and educational support for their child. Behaviors typical of ADHD occur more commonly in children who have experienced violence and emotional abuse.
Current models of ADHD suggest that it is associated with functional impairments in some of the brain's neurotransmitter systems, particularly those involving
Dopamine (DA, a contraction of 3,4-dihydroxyphenethylamine) is a neuromodulatory molecule that plays several important roles in cells. It is an organic chemical of the catecholamine and phenethylamine families. Dopamine constitutes about 8 ... and norepinephrine
Norepinephrine (NE), also called noradrenaline (NA) or noradrenalin, is an organic chemical in the catecholamine family that functions in the brain and body as both a hormone and neurotransmitter. The name "noradrenaline" (from Latin '' ad'' .... The dopamine and norepinephrine pathways that originate in the ventral tegmental area and locus coeruleus project to diverse regions of the brain and govern a variety of cognitive processes. The dopamine pathways and norepinephrine pathways which project to the prefrontal cortex and striatum are directly responsible for modulating executive function (cognitive control of behavior), motivation, reward perception, and motor function; these pathways are known to play a central role in the pathophysiology
Pathophysiology ( physiopathology) – a convergence of pathology with physiology – is the study of the disordered physiological processes that cause, result from, or are otherwise associated with a disease or injury. Pathology is th ... of ADHD. Larger models of ADHD with additional pathways have been proposed.
In children with ADHD, there is a general reduction of volume in certain brain structures, with a proportionally greater decrease in the volume in the left-sided prefrontal cortex.
The posterior parietal cortex
The posterior parietal cortex (the portion of parietal neocortex posterior to the primary somatosensory cortex) plays an important role in planned movements, spatial reasoning, and attention.
Damage to the posterior parietal cortex can produce a ... also shows thinning in individuals with ADHD compared to controls. Other brain structures in the prefrontal-striatal-cerebellar and prefrontal-striatal-thalamic circuits have also been found to differ between people with and without ADHD.
The subcortical volumes of the accumbens, amygdala
The amygdala (; plural: amygdalae or amygdalas; also '; Latin from Greek, , ', 'almond', 'tonsil') is one of two almond-shaped clusters of nuclei located deep and medially within the temporal lobes of the brain's cerebrum in complex verteb ..., caudate, hippocampus
The hippocampus (via Latin from Greek , ' seahorse') is a major component of the brain of humans and other vertebrates. Humans and other mammals have two hippocampi, one in each side of the brain. The hippocampus is part of the limbic system, ..., and putamen
The putamen (; from Latin, meaning "nutshell") is a round structure located at the base of the forebrain (telencephalon). The putamen and caudate nucleus together form the dorsal striatum. It is also one of the structures that compose the basal ... appears smaller in individuals with ADHD compared with controls. Structural MRI studies have also revealed differences in white matter, with marked differences in inter-hemispheric asymmetry between ADHD and typically developing youths
Functional MRI fMRI
Functional magnetic resonance imaging or functional MRI (fMRI) measures brain activity by detecting changes associated with blood flow. This technique relies on the fact that cerebral blood flow and neuronal activation are coupled. When an area o ... studies have revealed a number of differences between ADHD and control brains. Independent component analysis performed on resting-state fMRI data have revealed that individuals with the inattentive type of ADHD
Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterised by excessive amounts of inattention, hyperactivity, and impulsivity that are pervasive, impairing in multiple contexts, and otherwise age-inappro ... have significantly more independent components are required to describe the variance of this data.
Previously, it had been suggested that the elevated number of dopamine transporters in people with ADHD was part of the pathophysiology, but it appears the elevated numbers may be due to adaptation following exposure to stimulant medication.
Current models involve the mesocorticolimbic dopamine pathway and the locus coeruleus-noradrenergic system. ADHD psychostimulants possess treatment efficacy because they increase neurotransmitter activity in these systems. There may additionally be abnormalities in serotonergic, glutamatergic, or cholinergic pathways.
Executive function and motivation
The symptoms of ADHD arise from a deficiency in certain executive functions (e.g.,
Attentional control, colloquially referred to as concentration, refers to an individual's capacity to choose what they pay attention to and what they ignore. It is also known as endogenous attention or executive attention. In lay terms, attention ..., inhibitory control
Inhibitory control, also known as response inhibition, is a cognitive process – and, more specifically, an executive function – that permits an individual to inhibit their impulses and natural, habitual, or dominant behavioral r ..., and working memory
Working memory is a cognitive system with a limited capacity that can hold information temporarily. It is important for reasoning and the guidance of decision-making and behavior. Working memory is often used synonymously with short-term memory, ...). Executive functions are a set of cognitive processes that are required to successfully select and monitor behaviors that facilitate the attainment of one's chosen goals. The executive function impairments that occur in ADHD individuals result in problems with staying organised, time keeping, excessive procrastination
Procrastination is the action of unnecessarily and voluntarily delaying or postponing something despite knowing that there will be negative consequences for doing so. The word has originated from the Latin word ''procrastinatus'', which itself evo ..., maintaining concentration, paying attention, ignoring distractions, regulating emotions, and remembering details. People with ADHD appear to have unimpaired long-term memory, and deficits in long-term recall appear to be attributed to impairments in working memory. Due to the rates of brain maturation and the increasing demands for executive control as a person gets older, ADHD impairments may not fully manifest themselves until adolescence or even early adulthood.
ADHD has also been associated with motivational deficits in children. Children with ADHD often find it difficult to focus on long-term over short-term rewards, and exhibit impulsive behavior for short-term rewards.
Paradoxical reaction to neuroactive substances
Another sign of the structurally altered signal processing in the central nervous system in this group of people is the conspicuously common
Paradoxical reaction A paradoxical reaction (or paradoxical effect) is an effect of a chemical substance, such as a medical drug, that is opposite to what would usually be expected. An example of a paradoxical reaction is pain caused by a pain relief medication.
Parad ... (ca. 10–20 % of patients). These are unexpected reactions in the opposite direction as with a normal effect, or otherwise significant different reactions. These are reactions to neuroactive substances such as local anesthetic at the dentist, sedative
A sedative or tranquilliser is a substance that induces sedation by reducing irritability or excitement. They are CNS depressants and interact with brain activity causing its deceleration. Various kinds of sedatives can be distinguished, but t ..., caffeine
Caffeine is a central nervous system (CNS) stimulant of the methylxanthine class. It is mainly used recreationally as a cognitive enhancer, increasing alertness and attentional performance. Caffeine acts by blocking binding of adenosine ..., antihistamine
Antihistamines are drugs which treat allergic rhinitis, common cold, influenza, and other allergies. Typically, people take antihistamines as an inexpensive, generic (not patented) drug that can be bought without a prescription and provides ..., weak neuroleptics
Antipsychotics, also known as neuroleptics, are a class of psychotropic medication primarily used to manage psychosis (including delusions, hallucinations, paranoia or disordered thought), principally in schizophrenia but also in a range of oth ... and central and peripheral painkillers. Since the causes of ''paradoxical reactions'' are at least partly genetic, it may be useful in critical situations, for example before operations, to ask whether such abnormalities may also exist in family members. [B. Langguth, R. Bär, N. Wodarz, M. Wittmann, R. Laufkötter: ''Paradoxical reaction in ADHD.'' In: ''Deutsches Ärzteblatt international.'' Band 108, Nummer 31–32, August 2011, S. 541; author reply 541–541; author reply 542, (in German). doi:10.3238/arztebl.2011.0541a, PMID 21886668, .]
ADHD is diagnosed by an assessment of a person's behavioral and mental development, including ruling out the effects of drugs, medications, and other medical or psychiatric problems as explanations for the symptoms.
ADHD diagnosis often takes into account feedback from parents and teachers with most diagnoses begun after a teacher raises concerns. It may be viewed as the extreme end of one or more continuous human traits found in all people. Imaging studies of the brain do not give consistent results between individuals; thus, they are only used for research purposes and not a diagnosis.
In North America and Australia, DSM-5 criteria are used for diagnosis, while European countries usually use the ICD-10. The DSM-IV criteria for diagnosis of ADHD is more likely to diagnose ADHD than is the ICD-10 criteria. ADHD is alternately classified as neurodevelopmental disorder or a disruptive behavior disorder along with ODD, CD, and antisocial personality disorder
Antisocial personality disorder (ASPD or infrequently APD) is a personality disorder characterized by a long-term pattern of disregard of, or violation of, the rights of others as well as a difficulty sustaining long-term relationships. Lack .... A diagnosis does not imply a neurological disorder
A neurological disorder is any disorder of the nervous system. Structural, biochemical or electrical abnormalities in the brain, spinal cord or other nerves can result in a range of symptoms. Examples of symptoms include paralysis, muscle weaknes ....
Associated conditions that should be screened for include anxiety, depression, ODD, CD, and learning and language disorders. Other conditions that should be considered are other neurodevelopmental disorders, tics, and sleep apnea
Sleep apnea, also spelled sleep apnoea, is a sleep disorder in which pauses in breathing or periods of shallow breathing during sleep occur more often than normal. Each pause can last for a few seconds to a few minutes and they happen many time ....
Self-rating scales, such as the ADHD rating scale and the Vanderbilt ADHD diagnostic rating scale, are used in the screening and evaluation of ADHD. Electroencephalography is not accurate enough to make an ADHD diagnosis.
Diagnostic and Statistical Manual
As with many other psychiatric disorders, a formal diagnosis should be made by a qualified professional based on a set number of criteria. In the United States, these criteria are defined by the
American Psychiatric Association
The American Psychiatric Association (APA) is the main professional organization of psychiatrists and trainee psychiatrists in the United States, and the largest psychiatric organization in the world. It has more than 37,000 members are involv ... in the DSM. Based on the DSM-5 criteria published in 2013 and the DSM-5-TR criteria published in 2022, there are three presentations of ADHD: [
# ADHD, predominantly inattentive type, presents with symptoms including being easily distracted, forgetful, daydreaming, disorganization, poor concentration, and difficulty completing tasks.] [
# ADHD, predominantly hyperactive-impulsive type, presents with excessive fidgeting and restlessness, hyperactivity, and difficulty waiting and remaining seated.] [
# ADHD, combined type, is a combination of the first two presentations.] [
This subdivision is based on presence of at least six (in children) or five (in older teenagers and adults) out of nine long-term (lasting at least six months) symptoms of inattention, hyperactivity–impulsivity, or both.] [ To be considered, several symptoms must have appeared by the age of six to twelve and occur in more than one environment (e.g. at home and at school or work).] [ The symptoms must be inappropriate for a child of that age] [ and there must be clear evidence that they are causing social, school or work related problems.] [
The DSM-5 and the DSM-5-TR also provide two diagnoses for individuals who have symptoms of ADHD but do not entirely meet the requirements. ''Other Specified ADHD'' allows the clinician to describe why the individual does not meet the criteria, whereas ''Unspecified ADHD'' is used where the clinician chooses not to describe the reason.] [
International Classification of Diseases
In the eleventh revision of the ( ICD-11) by the
World Health Organization
The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level of ..., the disorder is classified as Attention deficit hyperactivity disorder (with the code 6A05). The defined subtypes are similar to those of the DSM-5: ''predominantly inattentive presentation'' (6A05.0); ''predominantly hyperactive-impulsive presentation''(6A05.1); ''combined presentation'' (6A05.2). However, the ICD-11 includes two residual categories for individuals who do not entirely match any of the defined subtypes: ''other specified presentation'' (6A05.Y) where the clinician includes detail on the individual's presentation; and ''presentation unspecified'' (6A05.Z) where the clinician does not provide detail.
In the tenth revision ( ICD-10
ICD-10 is the 10th revision of the International Statistical Classification of Diseases and Related Health Problems (ICD), a medical classification list by the World Health Organization (WHO). It contains codes for diseases, signs and symptoms, ...), the symptoms of ''hyperkinetic disorder'' were analogous to ADHD in the ICD-11. When a conduct disorder (as defined by ICD-10) is present, the condition was referred to as ''hyperkinetic conduct disorder''. Otherwise, the disorder was classified as ''disturbance of activity and attention'', ''other hyperkinetic disorders'' or ''hyperkinetic disorders, unspecified''. The latter was sometimes referred to as ''hyperkinetic syndrome''.
Social construct theory
The social construct theory of ADHD suggests that, because the boundaries between normal and abnormal behavior are socially constructed (i.e. jointly created and validated by all members of society, and in particular by
A physician (American English), medical practitioner (Commonwealth English), medical doctor, or simply doctor, is a health professional who practices medicine, which is concerned with promoting, maintaining or restoring health through the ...s, parents, teachers, and others), it then follows that subjective valuations and judgements determine which diagnostic criteria are used and thus, the number of people affected. This difference means using DSM-IV criteria could diagnose ADHD at rates three to four times higher than ICD-10 criteria. Thomas Szasz
Thomas Stephen Szasz ( ; hu, Szász Tamás István ; 15 April 1920 – 8 September 2012) was a Hungarian-American academic and psychiatrist. He served for most of his career as professor of psychiatry at the State University of New York Upstate ..., a supporter of this theory, has argued that ADHD was "invented and then given a name".
Adults with ADHD are diagnosed under the same criteria, including that their signs must have been present by the age of six to twelve. The individual is the best source for information in diagnosis, however others may provide useful information about the individual's symptoms currently and in childhood; a family history of ADHD also adds weight to a diagnosis.
While the core symptoms of ADHD are similar in children and adults, they often present differently in adults than in children: for example, excessive physical activity seen in children may present as feelings of restlessness and constant mental activity in adults.
Worldwide, it is estimated that 2.58% of adults have persistent ADHD (where the individual currently meets the criteria and there is evidence of childhood onset), and 6.76% of adults have symptomatic ADHD (meaning that they currently meet the criteria for ADHD, regardless of childhood onset). In 2020, this was 139.84 million and 366.33 million affected adults respectively. Around 15% of children with ADHD continue to meet full DSM-IV-TR criteria at 25 years of age, and 50% still experience some symptoms. , most adults remain untreated. Many adults with ADHD without diagnosis and treatment have a disorganised life, and some use non-prescribed drugs or alcohol as a coping mechanism. Other problems may include relationship and job difficulties, and an increased risk of criminal activities. Associated mental health problems include depression, anxiety disorders, and learning disabilities.
Some ADHD symptoms in adults differ from those seen in children. While children with ADHD may climb and run about excessively, adults may experience an inability to relax, or may talk excessively in social situations. Adults with ADHD may start relationships impulsively, display sensation-seeking behavior, and be short-tempered. Addictive behavior such as substance abuse and gambling
Gambling (also known as betting or gaming) is the wagering of something of value ("the stakes") on a random event with the intent of winning something else of value, where instances of strategy are discounted. Gambling thus requires three ele ... are common. This led to those who presented differently as they aged having outgrown the DSM-IV criteria. The DSM-5 criteria does specifically deal with adults unlike that of DSM-IV, which does not fully take into account the differences in impairments seen in adulthood compared to childhood.
For diagnosis in an adult, having symptoms since childhood is required. Nevertheless, a proportion of adults who meet the criteria for ADHD in adulthood would not have been diagnosed with ADHD as children. Most cases of late-onset ADHD develop the disorder between the ages of 12-16 and may therefore be considered early adult or adolescent-onset ADHD.
The DSM provides potential differential diagnoses - potential alternate explanations for specific symptoms. Assessment and investigation of clinical history determines which is the most appropriate diagnosis. The DSM-5 suggests ODD, intermittent explosive disorder, and other neurodevelopmental disorders (such as stereotypic movement disorder and Tourette's disorder), in addition to specific learning disorder, intellectual developmental disorder, ASD, reactive attachment disorder, anxiety disorders, depressive disorders, bipolar disorder, disruptive mood dysregulation disorder, substance use disorder, personality disorders, psychotic disorders, medication-induced symptoms, and neurocognitive disorders.
Many but not all of these are also common comorbidities of ADHD. The DSM-5-TR also suggests post-traumatic stress disorder. [
Symptoms of ADHD, such as low mood and poor self-image, mood swings, and irritability, can be confused with dysthymia, ] cyclothymia
Cyclothymia ( ), also known as cyclothymic disorder, psychothemia/psychothymia, bipolar III, affective personality disorder and cyclothymic personality disorder, is a mental and behavioural disorder that involves numerous periods of symptoms of ... or bipolar disorder
Bipolar disorder, previously known as manic depression, is a mental disorder characterized by periods of depression and periods of abnormally elevated mood that last from days to weeks each. If the elevated mood is severe or associated with ... as well as with borderline personality disorder
Borderline personality disorder (BPD), also known as emotionally unstable personality disorder (EUPD), is a personality disorder characterized by a long-term pattern of unstable interpersonal relationships, distorted sense of self, and strong .... Some symptoms that are due to anxiety disorders, personality disorder, developmental disabilities or intellectual disability or the effects of substance abuse such as intoxication and withdrawal can overlap with ADHD. These disorders can also sometimes occur along with ADHD. Medical conditions which can cause ADHD-type symptoms include: hyperthyroidism
Hyperthyroidism is the condition that occurs due to excessive production of thyroid hormones by the thyroid gland. Thyrotoxicosis is the condition that occurs due to excessive thyroid hormone of any cause and therefore includes hyperthyroidism. ..., seizure disorder, lead toxicity, hearing deficits, hepatic disease, sleep apnea
Sleep apnea, also spelled sleep apnoea, is a sleep disorder in which pauses in breathing or periods of shallow breathing during sleep occur more often than normal. Each pause can last for a few seconds to a few minutes and they happen many time ..., drug interaction
Drug interactions occur when a drug's mechanism of action is disturbed by the concomitant administration of substances such as foods, beverages, or other drugs. The cause is often the inhibition of the specific receptors available to the drug, ...s, untreated celiac disease
Coeliac disease (British English) or celiac disease (American English) is a long-term autoimmune disorder, primarily affecting the small intestine, where individuals develop intolerance to gluten, present in foods such as wheat, rye and barle ..., and head injury
A head injury is any injury that results in trauma to the skull or brain. The terms ''traumatic brain injury'' and ''head injury'' are often used interchangeably in the medical literature. Because head injuries cover such a broad scope of inju ....
Primary sleep disorders may affect attention and behavior and the symptoms of ADHD may affect sleep. It is thus recommended that children with ADHD be regularly assessed for sleep problems. Sleepiness in children may result in symptoms ranging from the classic ones of yawning and rubbing the eyes, to hyperactivity and inattentiveness. Obstructive sleep apnea
Obstructive sleep apnea (OSA) is the most common sleep-related breathing disorder and is characterized by recurrent episodes of complete or partial obstruction of the upper airway leading to reduced or absent breathing during sleep. These epis ... can also cause ADHD-type symptoms.
The management of ADHD typically involves
Counseling is the professional guidance of the individual by utilizing psychological methods especially in collecting case history data, using various techniques of the personal interview, and testing interests and aptitudes.
This is a list of co ... or medications, either alone or in combination. While treatment may improve long-term outcomes, it does not get rid of negative outcomes entirely. Medications used include stimulants, atomoxetine, alpha-2 adrenergic receptor
The alpha-2 (α2) adrenergic receptor (or adrenoceptor) is a G protein-coupled receptor (GPCR) associated with the Gi heterotrimeric G-protein. It consists of three highly homologous subtypes, including α2A-, α2B-, and α2C-adrenergic. Some ... agonists, and sometimes antidepressants. In those who have trouble focusing on long-term rewards, a large amount of positive reinforcement
In behavioral psychology, reinforcement is a consequence applied that will strengthen an organism's future behavior whenever that behavior is preceded by a specific antecedent stimulus. This strengthening effect may be measured as a higher fr ... improves task performance. ADHD stimulants also improve persistence and task performance in children with ADHD. "Recent evidence from observational and registry studies indicates that pharmacological treatment of ADHD is associated with increased achievement and decreased absenteeism at school, a reduced risk of trauma-related emergency hospital visits, reduced risks of suicide and attempted suicide, and decreased rates of substance abuse and criminality".
There is good evidence for the use of behavioral therapies in ADHD. They are the recommended first-line treatment in those who have mild symptoms or who are preschool-aged.
Psychological therapies used include: psychoeducational input, behavior therapy, cognitive behavioral therapy
Cognitive behavioral therapy (CBT) is a psycho-social intervention that aims to reduce symptoms of various mental health conditions, primarily depression and anxiety disorders. CBT focuses on challenging and changing cognitive distortions (su ..., interpersonal psychotherapy, family therapy
Family therapy (also referred to as family counseling, family systems therapy, marriage and family therapy, couple and family therapy) is a branch of psychology and clinical social work that works with families and couples in intimate relations ..., school-based interventions, social skills training, behavioral peer intervention, organization training, and parent management training
Parent management training (PMT), also known as behavioral parent training (BPT) or simply parent training, is a family of treatment programs that aims to change parenting behaviors, teaching parents positive reinforcement methods for improving pre .... Neurofeedback has greater treatment effects than non-active controls for up to 6 months and possibly a year following treatment, and may have treatment effects comparable to active controls (controls proven to have a clinical effect) over that time period. Despite efficacy in research, there is insufficient regulation of neurofeedback practice, leading to ineffective applications and false claims regarding innovations. Parent training may improve a number of behavioral problems including oppositional and non-compliant behaviors.
There is little high-quality research on the effectiveness of family therapy for ADHD—but the existing evidence shows that it is similar to community care, and better than placebo. ADHD-specific support groups can provide information and may help families cope with ADHD.
Social skills training, behavioral modification, and medication may have some limited beneficial effects in peer relationships. Stable, high-quality friendships with non-deviant peers protect against later psychological problems.
Methylphenidate, sold under the brand names Ritalin and Concerta among others, is the most widely prescribed central nervous system (CNS) stimulant medication used to treat attention deficit hyperactivity disorder (ADHD) and, to a lesser extent, ... and amphetamine
Amphetamine (contracted from alpha- methylphenethylamine) is a strong central nervous system (CNS) stimulant that is used in the treatment of attention deficit hyperactivity disorder (ADHD), narcolepsy, and obesity. It is also commonly used ... or its derivatives are first-line treatments for ADHD as they are considered the most effective pharmaceutical treatments. About 70 percent respond to the first stimulant tried and as few as 10 percent respond to neither amphetamines nor methylphenidate. Stimulants may also reduce the risk of unintentional injuries in children with ADHD. Magnetic resonance imaging
Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio wave ... studies suggest that long-term treatment with amphetamine or methylphenidate decreases abnormalities in brain structure and function found in subjects with ADHD. A 2018 review found the greatest short-term benefit with methylphenidate in children, and amphetamines in adults.
The likelihood of developing insomnia
Insomnia, also known as sleeplessness, is a sleep disorder in which people have trouble sleeping. They may have difficulty falling asleep, or staying asleep as long as desired. Insomnia is typically followed by daytime sleepiness, low energy, ... for ADHD patients taking stimulants has been measured at between 11 and 45 percent for different medications, and may be a main reason for discontinuation. Other side effects, such as tics, decreased appetite and weight loss, or emotional lability
In medicine and psychology, emotional lability is a sign or symptom typified by exaggerated changes in mood or affect in quick succession. Sometimes the emotions expressed outwardly are very different from how the person feels on the inside. Th ..., may also lead to discontinuation. Stimulant psychosis and mania
Mania, also known as manic syndrome, is a mental and behavioral disorder defined as a state of abnormally elevated arousal, affect, and energy level, or "a state of heightened overall activation with enhanced affective expression together wit ... are rare at therapeutic doses, appearing to occur in approximately 0.1% of individuals, within the first several weeks after starting amphetamine therapy. The safety of these medications in pregnancy is unclear. Symptom improvement is not sustained if medication is ceased.
The long-term effects of ADHD medication have yet to be fully determined, although stimulants are generally beneficial and safe for up to two years for children and adolescents.
Regular monitoring has been recommended in those on long-term treatment. There are indications suggesting that stimulant therapy for children and adolescents should be stopped periodically to assess continuing need for medication, decrease possible growth delay, and reduce tolerance. Although potentially addictive at high doses, stimulants used to treat ADHD have low potential for abuse. Treatment with stimulants is either protective against substance abuse or has no effect.
The majority of studies on nicotine
Nicotine is a naturally produced alkaloid in the nightshade family of plants (most predominantly in tobacco and '' Duboisia hopwoodii'') and is widely used recreationally as a stimulant and anxiolytic. As a pharmaceutical drug, it is used for ... and other nicotinic agonists as treatments for ADHD have shown favorable results; however, no nicotinic drug has been approved for ADHD treatment. Caffeine
Caffeine is a central nervous system (CNS) stimulant of the methylxanthine class. It is mainly used recreationally as a cognitive enhancer, increasing alertness and attentional performance. Caffeine acts by blocking binding of adenosine ... was formerly used as a second-line treatment for ADHD. It is considered less effective than methylphenidate or amphetamine but more so than placebo for children with ADHD. Pseudoephedrine and ephedrine
Ephedrine is a central nervous system (CNS) stimulant that is often used to prevent low blood pressure during anesthesia. It has also been used for asthma, narcolepsy, and obesity but is not the preferred treatment. It is of unclear benefit in ... do not affect ADHD symptoms.
Modafinil, sold under the brand name Provigil among others, is a central nervous system (CNS) stimulant medication used to treat sleepiness due to narcolepsy, shift work sleep disorder, and obstructive sleep apnea. While it has seen off-label ... has shown some efficacy in reducing the severity of ADHD in children and adolescents. It may be prescribed off-label to treat ADHD.
There are a number of non-stimulant medications, such as Viloxazine,
Atomoxetine, sold under the brand name Strattera, among others, is a medication used to treat attention deficit hyperactivity disorder (ADHD). It may be used alone or along with psychostimulants. It is also used as a cognitive enhancer to impr ..., bupropion, guanfacine, amantadine
Amantadine, sold under the brand name Gocovri among others, is a medication used to treat dyskinesia associated with parkinsonism and influenza caused by type A influenzavirus, though its use for the latter is no longer recommended due to wi ... (effective in children and adolescents but still not been seen for adults), and clonidine
Clonidine, sold under the brand name Catapres among others, is an α2-adrenergic agonist medication used to treat high blood pressure, ADHD, drug withdrawal (alcohol, opioids, or nicotine), menopausal flushing, diarrhea, spasticity, and certa ..., that may be used as alternatives, or added to stimulant therapy. There are no good studies comparing the various medications; however, they appear more or less equal with respect to side effects. For children, stimulants appear to improve academic performance while atomoxetine does not.
Atomoxetine, sold under the brand name Strattera, among others, is a medication used to treat attention deficit hyperactivity disorder (ADHD). It may be used alone or along with psychostimulants. It is also used as a cognitive enhancer to impr ..., due to its lack of addiction liability, may be preferred in those who are at risk of recreational or compulsive stimulant use, although evidence is lacking to support its use over stimulants for this reason. Evidence supports its ability to improve symptoms when compared to placebo.
Amantadine, sold under the brand name Gocovri among others, is a medication used to treat dyskinesia associated with parkinsonism and influenza caused by type A influenzavirus, though its use for the latter is no longer recommended due to wi ... was shown to induce similar improvements in children treated methylphenidate
Methylphenidate, sold under the brand names Ritalin and Concerta among others, is the most widely prescribed central nervous system (CNS) stimulant medication used to treat attention deficit hyperactivity disorder (ADHD) and, to a lesser extent, ..., with less frequent side effects. A 2021 retrospective study showed showed that amantadine may serve as an effective adjunct to stimulants for ADHD–related symptoms and appears to be a safer alternative to second- or third-generation antipsychotics.
There is little evidence on the effects of medication on social behaviors. Antipsychotics may also be used to treat aggression in ADHD.
A guideline is a statement by which to determine a course of action. A guideline aims to streamline particular processes according to a set routine or sound practice. Guidelines may be issued by and used by any organization (governmental or pri ... on when to use medications vary by country. The United Kingdom's National Institute for Health and Care Excellence
The National Institute for Health and Care Excellence (NICE) is an executive non-departmental public body of the Department of Health and Social Care in England that publishes guidelines in four areas:
* the use of health technologies with ... recommends use for children only in severe cases, though for adults medication is a first-line treatment. Conversely, most United States guidelines recommend medications in most age groups. Medications are especially not recommended for preschool children. Underdosing of stimulants can occur, and can result in a lack of response or later loss of effectiveness. This is particularly common in adolescents and adults as approved dosing is based on school-aged children, causing some practitioners to use weight-based or benefit-based off-label dosing instead.
Regular physical exercise, particularly aerobic exercise, is an effective add-on treatment for ADHD in children and adults, particularly when combined with stimulant medication (although the best intensity and type of aerobic exercise for improving symptoms are not currently known).
The long-term effects of regular aerobic exercise in ADHD individuals include better behavior and motor abilities, improved executive functions
In cognitive science and neuropsychology, executive functions (collectively referred to as executive function and cognitive control) are a set of cognitive processes that are necessary for the cognitive control of behavior: selecting and succe ... (including attention, inhibitory control, and planning
Planning is the process of thinking regarding the activities required to achieve a desired goal. Planning is based on foresight, the fundamental capacity for mental time travel. The evolution of forethought, the capacity to think ahead, is con ..., among other cognitive domains), faster information processing speed, and better memory. Parent-teacher ratings of behavioral and socio-emotional outcomes in response to regular aerobic exercise include: better overall function, reduced ADHD symptoms, better self-esteem, reduced levels of anxiety and depression, fewer somatic complaints, better academic and classroom behavior, and improved social behavior. Exercising while on stimulant medication augments the effect of stimulant medication on executive function. It is believed that these short-term effects of exercise are mediated by an increased abundance of synaptic dopamine and norepinephrine in the brain.
Dietary modifications are not recommended by the
American Academy of Pediatrics
The American Academy of Pediatrics (AAP) is an American professional association of pediatricians, headquartered in Itasca, Illinois. It maintains its Department of Federal Affairs office in Washington, D.C.
The Academy was founde ..., the National Institute for Health and Care Excellence, or the Agency for Healthcare Research and Quality
The Agency for Healthcare Research and Quality (AHRQ; pronounced "ark" by initiates and often "A-H-R-Q" by the public) is one of twelve agencies within the United States Department of Health and Human Services (HHS). The agency is headquartered i ... due to insufficient evidence.
A 2013 meta-analysis found less than a third of children with ADHD see some improvement in symptoms with free fatty acid
In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, f ... supplementation or decreased eating of artificial food coloring. These benefits may be limited to children with food sensitivities or those who are simultaneously being treated with ADHD medications. This review also found that evidence does not support removing other foods from the diet to treat ADHD. A 2014 review found that an elimination diet results in a small overall benefit in a minority of children, such as those with allergies. A 2016 review stated that the use of a gluten-free diet as standard ADHD treatment is not advised. A 2017 review showed that a few-foods elimination diet may help children too young to be medicated or not responding to medication, while free fatty acid supplementation or decreased eating of artificial food coloring as standard ADHD treatment is not advised. Chronic deficiencies of iron, magnesium and iodine may have a negative impact on ADHD symptoms. There is a small amount of evidence that lower tissue zinc levels may be associated with ADHD. In the absence of a demonstrated zinc deficiency
Zinc deficiency is defined either as insufficient zinc to meet the needs of the body, or as a serum zinc level below the normal range. However, since a decrease in the serum concentration is only detectable after long-term or severe depletion, s ... (which is rare outside of developing countries), zinc supplementation is not recommended as treatment for ADHD. However, zinc supplementation may reduce the minimum effective dose of amphetamine when it is used with amphetamine for the treatment of ADHD.
ADHD persists into adulthood in about 30–50% of cases.
Those affected are likely to develop coping mechanisms as they mature, thus compensating to some extent for their previous symptoms. Children with ADHD have a higher risk of unintentional injuries. Effects of medication on functional impairment and quality of life
Quality of life (QOL) is defined by the World Health Organization as "an individual's perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standard ... (e.g. reduced risk of accidents) have been found across multiple domains. Rates of smoking among those with ADHD are higher than in the general population at about 40%.
Individuals with ADHD are significantly overrepresented in prison populations. Although there is no generally accepted estimate of ADHD prevalence among inmates, a 2015 meta-analysis estimated a prevalence of 25.5%, and a larger 2018 meta-analysis estimated the frequency to be 26.2%. ADHD is more common among longer-term inmates; a 2010 study at Norrtälje Prison, a high-security prison in Sweden, found an estimated ADHD prevalence of 40%.
ADHD is estimated to affect about 6–7% of people aged 18 and under when diagnosed via the DSM-IV criteria.
When diagnosed via the ICD-10 criteria, rates in this age group are estimated around 1–2%. Children in North America appear to have a higher rate of ADHD than children in Africa and the Middle East; this is believed to be due to differing methods of diagnosis rather than a difference in underlying frequency. it was estimated to affect 84.7 million people globally. [. Both DSM-IV-TR and ICD-10 criteria were used.] If the same diagnostic methods are used, the rates are similar between countries. ADHD is diagnosed approximately three times more often in boys than in girls. This may reflect either a true difference in underlying rate, or that women and girls with ADHD are less likely to be diagnosed.
Rates of diagnosis and treatment have increased in both the United Kingdom and the United States since the 1970s. Prior to 1970, it was rare for children to be diagnosed with ADHD, while in the 1970s rates were about 1%. This is believed to be primarily due to changes in how the condition is diagnosed and how readily people are willing to treat it with medications rather than a true change in how common the condition is. It was believed changes to the diagnostic criteria in 2013 with the release of the DSM-5 would increase the percentage of people diagnosed with ADHD, especially among adults.
Due to disparities in the treatment and understanding of ADHD between caucasian and non-caucasian populations, many non-caucasian children go undiagnosed and unmedicated. It was found that within the US that there was often a disparity between caucasian and non-caucasian understandings of ADHD. This led to a difference in the classification of the symptoms of ADHD, and therefore, its misdiagnosis. It was also found that it was common in non-caucasian families and teachers to understand the symptoms of ADHD as behavioral issues, rather than mental illness.
Crosscultural differences in diagnosis of ADHD can also be attributed to the long-lasting effects of harmful, racially targeted medical practices. Medical pseudosciences, particularly those that targeted African American populations during the period of slavery in the US, lead to a distrust of medical practices within certain communities. The combination of ADHD symptoms often being regarded as misbehavior rather than as a psychiatric condition, and the use of drugs to regulate ADHD, result in a hesitancy to trust a diagnosis of ADHD. Cases of misdiagnosis in ADHD can also occur due to stereotyping of non-caucasian individuals. Due to ADHD's subjectively determined symptoms, medical professionals may diagnose individuals based on stereotyped behavior or misdiagnose due to differences in symptom presentation between Caucasian and non-Caucasian individuals.
Hyperactivity has long been part of the human condition. Sir Alexander Crichton describes "mental restlessness" in his book ''An inquiry into the nature and origin of mental derangement'' written in 1798. He made observations about children showing signs of being inattentive and having the "fidgets". The first clear description of ADHD is credited to George Still in 1902 during a series of lectures he gave to the Royal College of Physicians of London.
He noted both nature and nurture could be influencing this disorder.
Alfred Tredgold proposed an association between brain damage and behavioral or learning problems which was able to be validated by the encephalitis lethargica epidemic from 1917 through 1928.
The terminology used to describe the condition has changed over time and has included: ''minimal brain dysfunction'' in the DSM-I (1952), ''hyperkinetic reaction of childhood'' in the DSM-II (1968), and ''attention-deficit disorder with or without hyperactivity'' in the DSM-III (1980). In 1987, this was changed to ADHD in the DSM-III-R, and in 1994 the DSM-IV in split the diagnosis into three subtypes: ADHD inattentive type, ADHD hyperactive-impulsive type, and ADHD combined type. These terms were kept in the DSM-5 in 2013 and in the DSM-5-TR in 2022. [ Prior to the DSM, terms included ''minimal brain damage'' in the 1930s.
In 1934, Benzedrine became the first amphetamine medication approved for use in the United States.] Methylphenidate was introduced in the 1950s, and enantiopure
In chemistry, an enantiomer ( /ɪˈnænti.əmər, ɛ-, -oʊ-/ ''ih-NAN-tee-ə-mər''; from Ancient Greek ἐνάντιος ''(enántios)'' 'opposite', and μέρος ''(méros)'' 'part') – also called optical isomer, antipode, or optical anti ... dextroamphetamine in the 1970s. The use of stimulants to treat ADHD was first described in 1937. Charles Bradley gave the children with behavioral disorders Benzedrine and found it improved academic performance and behavior.
Once neuroimaging studies were possible, studies conducted in the 1990s provided support for the pre-existing theory that neurological differences - particularly in the frontal lobe
The frontal lobe is the largest of the four major lobes of the brain in mammals, and is located at the front of each cerebral hemisphere (in front of the parietal lobe and the temporal lobe). It is parted from the parietal lobe by a groove betw ...s - were involved in ADHD. During this same period, a genetic component was identified and ADHD was acknowledged to be a persistent, long-term disorder which lasted from childhood into adulthood.
ADHD was split into the current three sub-types because of a field trial completed by Lahey and colleagues.
ADHD, its diagnosis, and its treatment have been controversial since the 1970s.
The controversies involve clinicians, teachers, policymakers, parents, and the media. Positions range from the view that ADHD is within the normal range of behavior to the hypothesis that ADHD is a genetic condition. Other areas of controversy include the use of stimulant medications in children, the method of diagnosis, and the possibility of overdiagnosis. In 2009, the National Institute for Health and Care Excellence, while acknowledging the controversy, states that the current treatments and methods of diagnosis are based on the dominant view of the academic literature. In 2014, Keith Conners, one of the early advocates for recognition of the disorder, spoke out against overdiagnosis in a '' The New York Times
''The New York Times'' (''the Times'', ''NYT'', or the Gray Lady) is a daily newspaper based in New York City with a worldwide readership reported in 2020 to comprise a declining 840,000 paid print subscribers, and a growing 6 million paid ...'' article. In contrast, a 2014 peer-reviewed medical literature review indicated that ADHD is underdiagnosed in adults.
With widely differing rates of diagnosis across countries, states within countries, races, and ethnicities, some suspect factors other than the presence of the symptoms of ADHD are playing a role in diagnosis, such as cultural norms. Some sociologists consider ADHD to be an example of the medicalization
Medicalization is the process by which human conditions and problems come to be defined and treated as medical conditions, and thus become the subject of medical study, diagnosis, prevention, or treatment. Medicalization can be driven by new ev ... of deviant behavior, that is, the turning of the previously issue of school performance into a medical one. Most healthcare providers accept ADHD as a genuine disorder, at least in the small number of people with severe symptoms. Among healthcare providers the debate mainly centers on diagnosis and treatment in the much greater number of people with mild symptoms.
The nature and range of desirable endpoints of ADHD treatment vary among diagnostic standards for ADHD. In most studies, the efficacy of treatment is determined by reductions in ADHD symptoms. However, some studies have included subjective ratings from teachers and parents as part of their assessment of ADHD treatment efficacies. By contrast, the subjective ratings of children undergoing ADHD treatment are seldom included in studies evaluating the efficacy of ADHD treatments.
There have been notable differences in the diagnosis patterns of birthdays in school-age children. Those born relatively younger to the school starting age than others in a classroom environment are shown to be more likely diagnosed with ADHD. Boys who were born in December in which the school age cut-off was December 31 were shown to be 30% more likely to be diagnosed and 41% to be treated than others born in January. Girls born in December had a diagnosis percentage of 70% and 77% treatment more than ones born the following month. Children who were born at the last 3 days of a calendar year were reported to have significantly higher levels of diagnosis and treatment for ADHD than children born at the first 3 days of a calendar year. The studies suggest that ADHD diagnosis is prone to subjective analysis.
Possible positive traits
Possible positive traits of ADHD are a new avenue of research, and therefore limited.
A 2020 review found that creativity may be associated with ADHD symptoms, particularly divergent thinking
Divergent thinking is a thought process or method used to generate creative ideas by exploring many possible solutions. It typically occurs in a spontaneous, free-flowing, "non-linear" manner, such that many ideas are generated in an emergent c ... and quantity of creative achievements, but not with the disorder of ADHD itself – i.e. it has not been found to be increased in people diagnosed with the disorder, only in people with subclinical symptoms or those that possess traits associated with the disorder. Divergent thinking is the ability to produce creative solutions which differ significantly from each other and consider the issue from multiple perspectives. Those with ADHD symptoms could be advantaged in this form of creativity as they tend to have diffuse attention, allowing rapid switching between aspects of the task under consideration; flexible associative memory, allowing them to remember and use more distantly-related ideas which is associated with creativity; and impulsivity, which causes people with ADHD symptoms to consider ideas which others may not have. However, people with ADHD may struggle with convergent thinking, which is a cognitive process through which a set of obviously relevant knowledge is utilized in a focused effort to arrive at a single perceived best solution to a problem.
A 2020 article suggested that historical documentation supported Leonardo da Vinci
Leonardo di ser Piero da Vinci (15 April 14522 May 1519) was an Italian polymath of the High Renaissance who was active as a painter, draughtsman, engineer, scientist, theorist, sculptor, and architect. While his fame initially rested on h ...’s difficulties with procrastination and time management as characteristic of ADHD and that he was constantly on the go, but often jumping from task to task.
Possible biomarkers for diagnosis
Reviews of ADHD
In biomedical contexts, a biomarker, or biological marker, is a measurable indicator of some biological state or condition. Biomarkers are often measured and evaluated using blood, urine, or soft tissues to examine normal biological processes, pa ...s have noted that platelet monoamine oxidase expression, urinary norepinephrine
Norepinephrine (NE), also called noradrenaline (NA) or noradrenalin, is an organic chemical in the catecholamine family that functions in the brain and body as both a hormone and neurotransmitter. The name "noradrenaline" (from Latin '' ad'' ..., urinary MHPG, and urinary phenethylamine
Phenethylamine (PEA) is an organic compound, natural monoamine alkaloid, and trace amine, which acts as a central nervous system stimulant in humans. In the brain, phenethylamine regulates monoamine neurotransmission by binding to trace a ... levels consistently differ between ADHD individuals and non-ADHD controls. These measurements could potentially serve as diagnostic biomarkers for ADHD, but more research is needed to establish their diagnostic utility. Urinary and blood plasma
Blood plasma is a light amber-colored liquid component of blood in which blood cells are absent, but contains proteins and other constituents of whole blood in suspension. It makes up about 55% of the body's total blood volume. It is the in ... phenethylamine concentrations are lower in ADHD individuals relative to controls and the two most commonly prescribed drugs for ADHD, amphetamine
Amphetamine (contracted from alpha- methylphenethylamine) is a strong central nervous system (CNS) stimulant that is used in the treatment of attention deficit hyperactivity disorder (ADHD), narcolepsy, and obesity. It is also commonly used ... and methylphenidate
Methylphenidate, sold under the brand names Ritalin and Concerta among others, is the most widely prescribed central nervous system (CNS) stimulant medication used to treat attention deficit hyperactivity disorder (ADHD) and, to a lesser extent, ..., increase phenethylamine biosynthesis
Biosynthesis is a multi-step, enzyme-catalyzed process where substrates are converted into more complex products in living organisms. In biosynthesis, simple compounds are modified, converted into other compounds, or joined to form macromolecule ... in treatment-responsive individuals with ADHD. Lower urinary phenethylamine concentrations are also associated with symptoms of inattentiveness in ADHD individuals.
* National Institute of Mental Health
NIMH Pages About Attention-Deficit/Hyperactivity Disorder (ADHD).
National Institutes of Health (NIH), U.S. Department of Health and Human Services.
New Zealand Ministry of Health Guidelines for the Assessment and Treatment of Attention-Deficit/Hyperactivity Disorder
2 July 2001.
"Women and girls with ADHD" (video)
(17 April 2020), with Stephen P. Hinshaw and others, '' Knowable Magazine'' .
Ailments of unknown cause
Wikipedia medicine articles ready to translate (full)
Wikipedia neurology articles ready to translate