Date Published: 5 June 2006
Intermittent Explosive Disorder affects up to 16 million Americans
A little-known mental disorder characterized by episodes of unwarranted anger is more common than previously thought - according to a recent study funded by the United States organisation the National Institutes of Health.
Depending upon how broadly it is defined, intermittent explosive disorder (IED) affects as many as 7.3% of adults (so approx. 11.5 - 16 million Americans) at some time in their lives. The study is based on data from the National Comorbidity Survey Replication, a nationally representative, face-to-face household survey of 9,282 U.S. adults, conducted in 2001-2003.
People with IED are said to attack other peoples and their possessions, causing bodily injury and property damage. Typically beginning in the early teens, the disorder often precedes, and may predispose for, later depression, anxiety and substance abuse. Nearly 82% of those with IED also had one of these other disorders, yet only 28.8% ever received treatment for their anger, according to the report by Ronald Kessler, Ph.D. and his colleagues. In the June, 2006 Archives of General Psychiatry, they suggest that treating anger early might prevent some of these co-occurring disorders from developing.
To be diagnosed with IED, an individual must have had three episodes of impulsive aggressiveness "grossly out of proportion to any precipitating psychosocial stressor," at any time in their life, according to the standard psychiatric diagnostic manual. The person must have "all of a sudden lost control and broke or smashed something worth more than a few dollars?hit or tried to hurt someone?or threatened to hit or hurt someone."
People who had three such episodes within the space of one year, which is a more narrowly defined subgroup, were found to have a much more persistent and severe disorder, particularly if they attacked both people and property. The latter group caused 3.5 times more property damage than other violent IED sub-groups. Affecting nearly 4% of adults within any given year (approx. 5.9 - 8.5 million Americans) the disorder leads to a mean of 43 attacks over the course of a lifetime and is associated with substantial functional impairment.
Due to its earlier age-of-onset, identifying IED at an early stage, perhaps in school-based violence prevention programs, and providing early treatment might prevent some of the associated psychopathology. Although most study respondents with IED had seen a professional for emotional problems at some time in their lives, only 11.7% had been treated for their anger in the 12 months prior to the study interview.
Although the new prevalence estimates for IED are somewhat higher than previous studies have found, the researchers consider them conservative. For example, anger outbursts in people with bipolar disorder, which often overlaps with IED, were excluded. Previous studies have found little overlap between IED and other mental illnesses associated with impulsive violence, such as antisocial and borderline personality disorders.
Source: National Institutes of Health (NIH), U.S.A. -