Disinhibition

Certain psychoactive substances that have effects on the limbic system of the brain may induce disinhibition.

Clinical concept

Disinhibition in psychology is defined as a lack of inhibitory control manifested in several ways, affecting motor, instinctual, emotional, cognitive, and perceptual aspects with signs and symptoms, such as impulsivity, disregard for others and social norms, aggressive outbursts, misconduct, and oppositional behaviors, disinhibited instinctual drives including risk-taking behaviors and hypersexuality.

Brain injury

Disinhibition is a common symptom following brain injury, or lesions, particularly to the frontal lobe and primarily to the orbitofrontal cortex. The neuropsychiatric sequelae following brain injuries could include diffuse cognitive impairment, with more prominent deficits in the rate of information processing, attention, memory, cognitive flexibility, and problem-solving. Prominent impulsivity, affective instability, and disinhibition are seen frequently, secondary to injury to frontal, temporal, and limbic areas. In association with the typical cognitive deficits, these sequelae characterize the frequently noted "personality changes" in TBI (Traumatic Brain Injury) patients.

Disinhibition syndromes, in brain injuries and insults including brain tumors, strokes and epilepsy range from mildly inappropriate social behavior, and lack of control over one's behavior to the full-blown mania, depending on the lesions to specific brain regions. The previous several studies in brain traumas and insults have demonstrated significant associations between disinhibition syndromes and dysfunction of orbitofrontal and basotemporal cortices, affecting visuospatial functions, somatosensation, spatial memory, motoric, instinctive, affective, and intellectual behaviors.

Psychiatric disorder

Disinhibition syndromes have also been reported with mania-like manifestations in old age with lesions to the orbitofrontal and basotemporal cortex involving limbic and frontal connections (orbitofrontal circuit), especially in the right hemisphere. Behavioral disinhibition as a result of damage to frontal lobe could be seen as a result of consumption of alcohol and other central nervous system (CNS) depressants (e.g., benzodiazepines that disinhibit the frontal cortex from self-regulation and control). It has also been argued that the hyperactive/impulsive subtype of attention deficit hyperactivity disorder (ADHD) has a general behavioral disinhibition beyond impulsivity and many morbidities or complications of ADHD (e.g., conduct disorder, antisocial personality disorder, substance abuse, and risk-taking behaviors are all consequences of untreated behavioral disinhibition).

Personality disorder trait domain

Disinhibition is a pathological trait domain in two prominent dimensional models of personality disorders, namely the Alternative DSM-5 model for personality disorders and the ICD-11 classification of personality disorders. In the former, it is part of predefined specific personality disorders and can also be used for construction of a personality disorder–trait specified diagnosis. In the ICD-11 system, a unified personality disorder is instead classified by severity, with there also being a personality difficulty diagnosis for subclinical presentations. These diagnoses may be further specified by a qualifier, such as disinhibition in personality disorder or personality difficulty.