A mental disorder that encompasses a wide range of recurring, hostile outbursts, including domestic violence and road rage, characterizes considerably more people than previous data had indicated, a national survey finds.
At some point in their lives, between 5.4 percent and 7.3 percent of U.S. adults qualify for a diagnosis of intermittent explosive disorder, concludes a team led by sociologist Ronald C. Kessler of Harvard Medical School in Boston. Those percentages, which depend on whether the syndrome is narrowly or broadly defined, correspond to between 11.5 million and 16 million people, respectively.
In any given year, intermittent explosive disorder affects between 2.7 percent and 3.9 percent of adults, or from 5.9 million to 8.5 million people, Kessler and his coworkers report. “We never thought we’d find such high prevalence rates for this condition,” Kessler says.
In contrast, a 2004 study of 253 Baltimore residents estimated a lifetime prevalence of 4 percent for intermittent explosive disorder.
Intermittent explosive disorder features tirades, grossly disproportionate to the triggering circumstances, during which a person destroys property, tries to hurt or actually hurts someone, or threatens to do so. The expression of rage elicits a sense of relief, followed by remorse for the incident. The syndrome doesn’t include outbursts that stem from other mental disorders or from alcohol or drug effects.
For lifetime-prevalence figures in the new survey, broadly defined intermittent explosive disorder consisted of at least three such episodes during a person’s life. The narrowly defined version required three anger attacks in the same year.
For 1-year prevalence rates, the broad definition called for three or more anger attacks, at least one of which had occurred in the past year. The narrow definition required three attacks in the past year.
The findings, published in the June Archives of General Psychiatry, indicate that intermittent explosive disorder typically begins during adolescence and lasts for at least a decade, with an average of 43 episodes per person. A majority of those incidents targeted spouses or children, with potentially harmful effects on their emotional health (SN: 5/27/06, p. 323: Available to subscribers at Burden of Abuse: Violent partners take mental toll on women). During young adulthood or middle age, most people with intermittent explosive disorder developed other mental disorders, usually depression, anxiety, or substance abuse.
Kessler’s team analyzed data from in-person interviews with a nationally representative sample of 9,282 adults, age 18 and older.
Researchers now need to examine whether youngsters with intermittent explosive disorder who are treated with cognitive therapy, relaxation training, or psychiatric medications avoid later depression or other mental disorders, Kessler says.
The new survey offers a preliminary, possibly excessive estimate of intermittent explosive disorder’s reach, remarks psychiatrist Darrel A. Regier, director of the American Psychiatric Association’s office of research in Arlington, Va. Since clinicians didn’t validate the diagnoses with detailed assessments, prevalence rates may have included people whose angry reactions fell within a normal range of responses to stressful situations, Regier notes.
“I take these prevalence estimates with a big grain of salt,” he says.
It’s unclear whether anger attacks by children and teens represent initial symptoms of broader problems, such as attention-deficit hyperactivity disorder or mood disorders, adds psychiatrist William E. Narrow of the American Psychiatric Association.