Among a clinical population, a 2005 study found the lifetime prevalence of IED to be 6.3%.Prevalence appears to be higher in men than in women.Of US subjects with IED, 67.8% had engaged in direct interpersonal aggression, 20.9% in threatened interpersonal aggression, and 11.4% in aggression against objects. Subjects reported engaging in 27.8 high-severity aggressive acts during their worst year, with 2–3 outbursts requiring medical attention. Across the lifespan, the mean value of property damage due to aggressive outbursts was $1603.A study in the March 2016 Journal of Clinical Psychiatry suggests a relationship between infection with the parasite Toxoplasma gondii and psychiatric aggression such as IED. History
In the first edition of the American Psychiatric Associations Diagnostic and Statistical Manual (DSM-I), a disorder of impulsive aggression was referred to as a passive-aggressive personality type (aggressive type). This construct was characterized by a "persistent reaction to frustration are "generally excitable, aggressive, and over-responsive to environmental pressures" with "gross outbursts of rage or of verbal or physical aggressiveness different from their usual behavior".In the third edition (DSM-III), this was for the first time codified as intermittent explosive disorder and assigned clinical disorder status under Axis I. However, some researchers saw the criteria as poorly operationalized. About 80% of individuals who would now be diagnosed with the disorder would have been excluded.In the DSM-IV, the criteria were improved but still lacked objective criteria for the intensity, frequency, and nature of aggressive acts to meet criteria for IED.
Intermittent explosive disorder (sometimes abbreviated as IED) is a behavioral disorder characterized by explosive outbursts of anger and/or violence, often to the point of rage, that are disproportionate to the situation at hand (e.g., impulsive shouting, screaming or excessive reprimanding triggered by relatively inconsequential events). Impulsive aggression is not premeditated, and is defined by a disproportionate reaction to any provocation, real or perceived. Some individuals have reported affective changes prior to an outburst, such as tension, mood changes, energy changes, etc.The disorder is currently categorized in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) under the "Disruptive, Impulse-Control, and Conduct Disorders" category. The disorder itself is not easily characterized and often exhibits comorbidity with other mood disorders, particularly bipolar disorder. Individuals diagnosed with IED report their outbursts as being brief (lasting less than an hour), with a variety of bodily symptoms (sweating, stuttering, chest tightness, twitching, palpitations) reported by a third of one sample. Aggressive acts are frequently reported to be accompanied by a sensation of relief and in some cases pleasure, but often followed by later remorse. Pathophysiology
Impulsive behavior, and especially impulsive violence predisposition, have been correlated to a low brain serotonin turnover rate, indicated by a low concentration of 5-hydroxyindoleacetic acid (5-HIAA) in the cerebrospinal fluid (CSF). This substrate appears to act on the suprachiasmatic nucleus in the hypothalamus, which is the target for serotonergic output from the dorsal and median raphe nuclei playing a role in maintaining the circadian rhythm and regulation of blood sugar.