Intermittent explosive disorder (IED) is not yet on the radar screens of many psychiatrists, but it is more prevalent than panic disorder and warrants extensive research and attention, 2 experts on IED said recently.
In exclusive interviews, Ronald Kessler, PhD, professor of health care policy at Harvard Medical School, and Emil Coccaro, MD, Ellen C. Manning professor and chair of the University of Chicago's department of psychiatry, discussed their recently released study of the prevalence and correlates of IED1 and current as well as planned treatment research.
Depending on how it is defined, IED affects between 5.4% and 7.3% of adults (11.5 to 16 million Americans) in their lifetimes. The prevalence study, funded by the National Institute of Mental Health, was based on data from the National Comorbidity Survey Replication, a national representative, face-to-face household survey of 9282 US adults aged 18 years and older. The diagnoses used in that survey emanated from version 3.0 of the World Health Organization Composite International Diagnostic Interview, which included an assessment of DSM-IV IED.
Findings of the survey indicate that IED is a lot more common than it was previously thought to be, Kessler told Psychiatric Times. It is more common than panic disorder, and anger attacks are more common than panic attacks.
"When you look at the impairment data about the impact on people's lives, IED is very important there, too, because it not only affects the person who has it, but . . . the people around the person with the disorder—the people whom the lamp gets thrown at rather than the person who is throwing the lamp," Kessler added. "Isn't it amazing that something this important has been going on . . . under the radar screen?"
Explaining why IED has gone relatively unnoticed in the psychiatric community, Kessler pointed out that people who are angry have not traditionally sought help in the same way as people who are depressed or anxious. Most of the persons with IED identified in the prevalence study were found to have received treatment for emotional problems at some time in their life but not for their anger.
"So what it is telling us is that a lot of these people are sitting in mental health professionals' offices, but the clinicians don't ask and the patients don't volunteer that they have this problem," Kessler said. "They are there talking about their alcoholism, depression, or anxiety, but not about their anger."
Mental health professionals don't ask about anger, Kessler speculated, because they don't know what to do once they find out about it. Another contributing factor to underappreciation of the prevalence of IED, he said, relates to the varied and changing conceptualizations of the disorder in different diagnostic systems. Coccaro confirmed that "the criteria were never very good in the DSMs," making it more difficult to conduct research on the disorder.
1. Kessler RC, Coccaro EF, Fava M, et al. The prevalence and correlates of DSM-IV intermittent explosive disorder in the National Comorbidity Survey Replication. Arch Gen Psychiatry. 2006;63:669-678.
2. Dougherty DD, Rauch SL, Deckersbach T, et al. Ventromedial prefrontal cortex and amygdala dysfunction during an anger induction positron emission tomography study in patients with major depressive disorder with anger attacks. Arch Gen Psychiatry. 2004;61:795-804.