Thought blocking is a type of

thought disorder A thought disorder (TD) is any disturbance in cognition that adversely affects language and thought content, and thereby communication. A variety of thought disorders were said to be characteristic of people with schizophrenia. A content-though ...

in which a person will suddenly and involuntarily fall silent, or abruptly change to another subject. When thought blocking, some people may express themselves in a manner that is not understandable to others. They may repeat words involuntarily or make up new words. When doctors diagnose thought blocking they consider a variety of causes, such as

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 w ...

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 ...

petit mal seizure Absence seizures are one of several kinds of generalized seizures. These seizures are sometimes referred to as petit mal seizures (from the French for "little illness", a term dated in the late 18th century). Absence seizures are characterized by ...

s, dissociation, bradyphrenia,

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 ...

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 ...

delirium Delirium (also known as acute confusional state) is an organically caused decline from a previous baseline of mental function that develops over a short period of time, typically hours to days. Delirium is a syndrome encompassing disturbances ...

Schizophrenia

Thought blocking occurs most often in people with psychiatric illnesses, most commonly

. A person's speech is suddenly interrupted by silences that may last a few seconds to a minute or longer. When the person begins speaking again, after the block, they will often speak about an unrelated subject. Blocking is also described as an experience of unanticipated, quick and total emptying of the mind.Gelder, Mayou, Geddes (2005). Psychiatry. New York, NY; Oxford University Press Inc. People with schizophrenia commonly experience thought blocking and may interpret the experience in peculiar ways. For example, a person with schizophrenia might remark that another person has removed their thoughts from their brain. When evaluating a patient for schizophrenia, a physician may look for thought blocking. In schizophrenia, patients experience two types of symptoms: positive and negative. Positive symptoms include behavior added on to a person's daily functioning. For instance,

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 ...

hallucination A hallucination is a perception in the absence of an external stimulus that has the qualities of a real perception. Hallucinations are vivid, substantial, and are perceived to be located in external objective space. Hallucination is a combinati ...

s, disorganized speech, disorganized behavior and thought are all positive symptoms. In contrast, negative symptoms are characterized by missing parts of the average individual's persona, including flat affect,

apathy Apathy is a lack of feeling, emotion, interest, or concern about something. It is a state of indifference, or the suppression of emotions such as concern, excitement, motivation, or passion. An apathetic individual has an absence of inter ...

, speaking very little, not finding enjoyment in any activity, and not attending to basic acts of daily living (ADLs), such as bathing, eating, and wearing clean clothes.

Anxiety

Generalized anxiety disorder (GAD) is defined as excessive worry about matters in two or more separate subjects for at least six months. When a person experiences an anxiety attack, they may become so hyperfocused on the distressing stimuli and/or overwhelmed with the situation that regular speech is difficult for that person to produce. The thought blocking that occurs in this instance is usually short lived because anxiety attacks are transient. After an episode occurs, a person is typically able to resume their normal way of speaking.

Seizures

Thought blocking is associated with

. As such, it can be hard for people to organize their speech, resulting in thought blocking.

Dissociation and Post-traumatic stress disorder (PTSD)

Post-traumatic stress disorder (PTSD) is a psychiatric disorder that can occur after a person experiences a traumatic event and is significantly handicapped because of it, and can develop inappropriate coping strategies. These maladaptive approaches can include, but are not limited to, dissociative symptoms:

depersonalization Depersonalization can consist of a detachment within the self, regarding one's mind or body, or being a detached observer of oneself. Subjects feel they have changed and that the world has become vague, dreamlike, less real, lacking in significa ...

and

derealization Derealization is an alteration in the perception of the external world, causing those with the condition to perceive it as unreal, distant, distorted or falsified. Other symptoms include feeling as if one's environment is lacking in spontaneity, ...

. When these dissociative symptoms surface, they can be extremely intrusive and result in a person not being able to focus on their diction, or manner of speaking, and result in thought blocking. People with PTSD may find that blocking of thought occurs more often if they have not addressed the source of their PTSD.

Cognitive & Motor Disorder

In older adults, blocking of thought can be a feature of several cognitive and motor disorders, including underlying

and

. It is common that as a person ages, they may become forgetful and/or lose their train of thought. When it becomes more persistent and affects one's ability to carry out their ADLs (activities of daily living), a major neurocognitive disorder like

is among the possible causes. In addition, thought blocking can occur in patients with parkinsonism, a disorder that features slowing of movement, muscle rigidity, and impairment. The distinguishing feature between parkinsonism and

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 beco ...

is that the causes of

parkinsonism Parkinsonism is a clinical syndrome characterized by tremor, bradykinesia (slowed movements), rigidity, and postural instability. These are the four motor symptoms found in Parkinson's disease (PD), after which it is named, dementia with Lew ...

are numerous, including drugs, toxins, metabolic disorders, and head trauma. Furthermore, a stroke can result in a disordered speech process such as thought blocking. When a stroke affects the

middle cerebral artery The middle cerebral artery (MCA) is one of the three major paired cerebral arteries that supply blood to the cerebrum. The MCA arises from the internal carotid artery and continues into the lateral sulcus where it then branches and projects to ma ...

(MCA), it can result in damage to the

Wernicke's area Wernicke's area (; ), also called Wernicke's speech area, is one of the two parts of the cerebral cortex that are linked to speech, the other being Broca's area. It is involved in the comprehension of written and spoken language, in contrast to B ...

Broca's area Broca's area, or the Broca area (, also , ), is a region in the frontal lobe of the dominant hemisphere, usually the left, of the brain with functions linked to speech production. Language processing has been linked to Broca's area since Pier ...

. As such, people afflicted can understand speech well but have problems saying the words they want to, or be able to speak but have nonsensical syntax and word choice. These symptoms are referred to as

s, and aphasias can present with thought blocking.

References

{{Reflist Thought disorders