In
medicine
Medicine is the science and practice of caring for a patient, managing the diagnosis, prognosis, prevention, treatment, palliation of their injury or disease, and promoting their health. Medicine encompasses a variety of health care pr ...
, a prodrome is an early
sign or
symptom (or set of signs and symptoms) that often indicates the onset of a
disease
A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...
before more diagnostically specific signs and symptoms develop. It is derived from the Greek word ''prodromos'', meaning "running before". Prodromes may be
non-specific symptoms
Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showin ...
or, in a few instances, may clearly indicate a particular disease, such as the prodromal
migraine aura
An aura is a perceptual disturbance experienced by some with epilepsy or migraine. An epileptic aura is a seizure.
Epileptic and migraine auras are due to the involvement of specific areas of the brain, which are those that determine the symptom ...
.
For example,
fever
Fever, also referred to as pyrexia, is defined as having a temperature above the normal range due to an increase in the body's temperature set point. There is not a single agreed-upon upper limit for normal temperature with sources using val ...
,
malaise,
headache and lack of appetite frequently occur in the prodrome of many
infective disorders. A prodrome can be the early precursor to an episode of a chronic
neurological disorder such as a
migraine headache or an
epileptic seizure
An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with los ...
, where prodrome symptoms may include
euphoria or other changes in
mood,
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, ...
,
abdominal sensations, disorientation,
aphasia
Aphasia is an inability to comprehend or formulate language because of damage to specific brain regions. The major causes are stroke and head trauma; prevalence is hard to determine but aphasia due to stroke is estimated to be 0.1–0.4% in t ...
, or
photosensitivity Photosensitivity is the amount to which an object reacts upon receiving photons, especially visible light. In medicine, the term is principally used for abnormal reactions of the skin, and two types are distinguished, photoallergy and phototoxicit ...
. Such a prodrome occurs on a scale of days to an hour before the episode, where an
aura occurs more immediate to it.
Prodromal labour, mistakenly called "false labour," refers to the early signs before labour starts.
In mental health
The prodrome is a period during which an individual experiences some
symptoms and/or a change in functioning, which can signal the impending onset of a mental health disorder. It is otherwise known as the prodromal phase when referring to the
subsyndromal stage or the early
abnormalities in behavior, mood, and/or cognition before illness onset. Early detection of the prodrome can create an opportunity to administer appropriate early interventions quickly to try to delay or decrease the intensity of subsequent symptoms.
Schizophrenia
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 ...
was the first disorder for which a
prodromal stage was described.
People who go on to develop schizophrenia commonly experience non-specific negative symptoms such as
depression,
anxiety
Anxiety is an emotion which is characterized by an unpleasant state of inner turmoil and includes feelings of dread over anticipated events. Anxiety is different than fear in that the former is defined as the anticipation of a future threat wh ...
symptoms, and
social isolation
Social isolation is a state of complete or near-complete lack of contact between an individual and society. It differs from loneliness, which reflects temporary and involuntary lack of contact with other humans in the world. Social isolation ...
.
This is often followed by the emergence of attenuated
positive symptoms such as problems with communication, perception, and unusual thoughts that don't rise to the level of
psychosis
Psychosis is a condition of the mind that results in difficulties determining what is real and what is not real. Symptoms may include delusions and hallucinations, among other features. Additional symptoms are incoherent speech and behavior ...
.
Closer to the onset of psychosis, people often exhibit more serious symptoms like pre-
delusion
A delusion is a false fixed belief that is not amenable to change in light of conflicting evidence. As a pathology, it is distinct from a belief based on false or incomplete information, confabulation, dogma, illusion, hallucination, or som ...
al unusual thoughts, pre-
hallucinatory perceptual abnormalities or pre-thought disordered speech disturbances.
As positive symptoms become more severe, in combination with
negative symptoms
Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showin ...
that may have begun earlier, the individual may meet the diagnostic criteria for schizophrenia.
Although a majority of individuals who experience some of the symptoms of schizophrenia will never meet full diagnostic criteria, approximately 20–40% will eventually be diagnosed with schizophrenia.
One of the challenges of identifying and treating the prodrome is that it is difficult to predict who, among those with symptoms, are likely to meet full criteria later.
Duration
The prodromal phase in schizophrenia can last anywhere from several weeks to several years, and
comorbid disorders, such as
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. Intro ...
, are common during this period.
Identification/assessments
Screening instruments include the Scale of Prodromal Symptoms
and the PROD-screen.
Signs and symptoms of the prodrome to schizophrenia can be assessed more fully using
structured interview A structured interview (also known as a standardized interview or a researcher-administered survey) is a quantitative research method commonly employed in survey research. The aim of this approach is to ensure that each interview is presented with e ...
s. For example, the Structured Interview for Prodromal Syndromes,
[ and the Comprehensive Assessment of At Risk Mental States (CAARMS) are both valid and reliable methods for identifying individuals likely experiencing the prodrome to schizophrenia or related psychotic-spectrum disorders.
There are ongoing research efforts to develop tools for early detection of at-risk individuals. This includes development of risk calculators and methods for large-scale population screening.
]
Interventions
Describing the schizophrenia prodrome has been useful in promoting early intervention
Early childhood intervention (ECI) is a support and educational system for very young children (aged birth to six years) who have been victims of, or who are at high risk for child abuse and/or neglect as well as children who have developmental de ...
. Although not all people who are experiencing symptoms consistent with the prodrome will develop schizophrenia, randomized controlled trial
A randomized controlled trial (or randomized control trial; RCT) is a form of scientific experiment used to control factors not under direct experimental control. Examples of RCTs are clinical trials that compare the effects of drugs, surgical te ...
s suggest that intervening with medication and/or psychotherapy can improve outcomes. Interventions with evidence of efficacy include antipsychotic
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 ...
and antidepressant medications, which can delay conversion to psychosis and improve symptoms, although prolonged exposure to antipsychotics has been associated with adverse effects including Tardive dyskinesia
Tardive dyskinesia (TD) is a disorder that results in involuntary repetitive body movements, which may include grimacing, sticking out the tongue or smacking the lips. Additionally, there may be rapid jerking movements or slow writhing movemen ...
, an irreversible neurological motor disorder. Psychotherapy for individuals and families can also improve functioning and symptomatology; specifically cognitive behavioral therapy (CBT) helps improve coping strategies to decrease positive psychosis symptoms. Additionally, omega-3 fish oil supplements may help reduce prodromal symptoms. Current guidelines suggest that individuals who are at “high risk” for developing schizophrenia should be monitored for at least one to two years while receiving psychotherapy and medication, as needed, to treat their symptoms.
Bipolar disorder
Symptomology
There is also growing evidence that there is a prodromal phase before the onset of bipolar disorder (BD). Although a majority of individuals with bipolar disorder report experiencing some symptoms preceding the full onset of their illness, the prodrome to BD has not yet been described systematically. Descriptive reports of bipolar prodrome symptoms vary and often focus on nonspecific symptoms of psychopathology, making identification of the prodromal phase difficult. The most commonly observed symptoms are too much energy, elated or depressed mood, and alterations in sleep patterns. There are no prospective studies of the prodrome to bipolar disorder, but in the Longitudinal Assessment of Manic Symptoms (LAMS) study, which followed youth with elevated symptoms of mania for ten years, approximately 23% of the sample met BD criteria at the baseline and 13% of which did not meet the criteria for BD at baseline eventually were diagnosed with BD.
Duration
The reported duration of the prodrome to BD varies widely (mean = 27.1 ± 23 months); for most people, evidence suggests that the prodromal phase is likely to be long enough to allow for intervention.
Identification/assessments
Symptoms consistent with the prodrome to BD can be identified through semi-structured interview
A semi-structured interview is a method of research used most often in the social sciences. While a structured interview has a rigorous set of questions which does not allow one to divert, a semi-structured interview is open, allowing new ideas to ...
s such as The Bipolar Prodrome Symptom Interview and Scale-Prospective (BPSS-P), and the Semi-structured Interview for Mood Swings and symptom checklists like the Young Mania Rating Scale (YMRS) and the Hamilton Depression Scale (HAM-D).
Interventions
Early intervention is associated with better outcomes for people with prodromal symptoms of BD. Interventions with some evidence of efficacy include medication (e.g. mood stabilizers, atypical antipsychotic
The atypical antipsychotics (AAP), also known as second generation antipsychotics (SGAs) and serotonin–dopamine antagonists (SDAs), are a group of antipsychotic drugs (antipsychotic drugs in general are also known as major tranquilizers and ne ...
s) and psychotherapy. Specifically, family-focused therapy improves emotion regulation and enhances functioning in both adults and adolescents. Interpersonal and Social Rhythm Therapy (IPSRT) may be beneficial for youth at risk of developing BD by helping to stabilize their sleep and circadian patterns. Psychoeducational Psychotherapy (PEP) may be protective in individuals at risk of developing bipolar disorder and are associated with a four-fold reduction in risk for conversion to BD. This research needs to be explored further, however, it is currently thought to produce improvements in decreased stress due to social support and improved functioning through the skills developed in PEP. PEP can prove especially beneficial for individuals presenting transitional mania symptoms as it can assist caregivers in recognizing prodromal mania symptoms and knowing the next steps towards early intervention. The key goals of this type of therapy are to provide psychoeducation about 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 St ...
s and treatments, social support, and to build skills in symptom management, emotion regulation, and problem-solving and communication. This research is in its infancy, further investigations will be necessary to determine which methods lead to the best outcomes and for whom.
In neurological conditions
Neurodegenerative diseases
Several neurodegenerative
A neurodegenerative disease is caused by the progressive loss of structure or function of neurons, in the process known as neurodegeneration. Such neuronal damage may ultimately involve cell death. Neurodegenerative diseases include amyotrophic ...
diseases have a prodromal phase. Early impairments in behavior, personality and language may be detected in Alzheimer's disease. In dementia with Lewy bodies
Dementia with Lewy bodies (DLB) is a type of dementia characterized by changes in sleep, behavior, cognition, movement, and regulation of automatic bodily functions. Memory loss is not always an early symptom. The disease worsens over time an ...
, there is an identifiable set of early signs and symptoms that can appear 15 years or more before dementia
Dementia is a disorder which manifests as a set of related symptoms, which usually surfaces when the brain is damaged by injury or disease. The symptoms involve progressive impairments in memory, thinking, and behavior, which negatively affe ...
develops. The earliest symptoms are constipation
Constipation is a bowel dysfunction that makes bowel movements infrequent or hard to pass. The stool is often hard and dry. Other symptoms may include abdominal pain, bloating, and feeling as if one has not completely passed the bowel movement ...
and dizziness
Dizziness is an imprecise term that can refer to a sense of disorientation in space, vertigo, or lightheadedness. It can also refer to disequilibrium or a non-specific feeling, such as giddiness or foolishness.
Dizziness is a common medical c ...
from autonomic dysfunction
Dysautonomia or autonomic dysfunction is a condition in which the autonomic nervous system (ANS) does not work properly. This may affect the functioning of the heart, bladder, intestines, sweat glands, pupils, and blood vessels. Dysautonomia has ...
, hyposmia
Hyposmia, or microsmia, is a reduced ability to smell and to detect odors. A related condition is anosmia, in which no odors can be detected. Some of the causes of olfaction problems are allergies, nasal polyps, viral infections and head trauma. ...
(reduced ability to smell), visual hallucinations, and rapid eye movement sleep behavior disorder
Rapid eye movement sleep behavior disorder or REM behavior disorder (RBD) is a sleep disorder in which people act out their dreams. It involves abnormal behavior during the sleep phase with rapid eye movement (REM) sleep. The major feature of ...
(RBD). RBD may appear years or decades before other symptoms. In Parkinson's disease
Parkinson's disease (PD), or simply Parkinson's, is a long-term degenerative disorder of the central nervous system that mainly affects the motor system. The symptoms usually emerge slowly, and as the disease worsens, non-motor symptoms becom ...
the loss of sense of smell may aid in earlier diagnosis.[ ] Multiple sclerosis may have a prodromal phase.
Migraine
The prodromal phase of migraine is not always present, and varies from individual to individual, but can include ocular disturbances such as shimmering lights with reduced vision, altered mood, irritability, depression or euphoria, fatigue, yawning
A yawn is a reflex lasting 4-7 seconds, and is characterized by a long inspiratory phase with gradual mouth gaping, followed by a brief climax (or acme) with muscle stretching, and a rapid expiratory phase with muscle relaxation. For fish an ...
, excessive sleepiness, craving for certain food (e.g. chocolate
Chocolate is a food made from roasted and ground cacao seed kernels that is available as a liquid, solid, or paste, either on its own or as a flavoring agent in other foods. Cacao has been consumed in some form since at least the Olmec civ ...
), stiff muscles (especially in the neck), hot ears, constipation or diarrhea, increased urination, and other visceral symptoms.
In other diseases
Diverticulitis may worsen throughout the first day, as it starts out as small pains in the torso and/or mild diarrhea
Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin w ...
, and may slowly turn into vomiting and sharp pains in the lower left quadrant of the abdomen.
The prodromal phase of herpes simplex
Herpes simplex is a viral infection caused by the herpes simplex virus. Infections are categorized based on the part of the body infected.
Oral herpes involves the face or mouth. It may result in small blisters in groups often called col ...
is marked by tingling ( paresthesia), itching, and pain.
Prodromal measles is marked by fever
Fever, also referred to as pyrexia, is defined as having a temperature above the normal range due to an increase in the body's temperature set point. There is not a single agreed-upon upper limit for normal temperature with sources using val ...
, rhinorrhea
Rhinorrhea, rhinorrhoea, or informally runny nose is the free discharge of a thin mucus fluid from the nose; it is a common condition. It is a common symptom of allergies ( hay fever) or certain viral infections, such as the common cold or CO ...
, and conjuctivitis. Varicella may feature a prodrome; at least 37% of unvaccinated children who contract chickenpox have at ''least'' a mild febrile prodrome.
See also
* Apophenia
* Postdrome
References
External links
*
*
*
{{Bipolar disorder
Early psychosis
Symptoms
Schizophrenia