I’m Steve Ember with the VOA Special English Health Report.

Lots of people get angry in traffic.  But some people get really angry.  This hostility can lead to aggressive actions or, in some cases, violence.  Angry drivers have been known to pull out a gun or cause a crash.  For years people have called it road rage.  Now we are hearing a medical name. 

Experts say that in some cases, these actions are linked to a deeper problem: intermittent explosive disorder, or I.E.D.  It means that from time to time people explode in anger.  They may attack others or damage property.  Medical experts say this disorder is caused by an imbalance in brain chemicals. 

The National Institute of Mental Health recently paid for a study of intermittent explosive disorder.  Researchers at Harvard Medical School and Massachusetts General Hospital in Boston and at the University of Chicago did the work.

The researchers used information from a study of more than nine thousand adults in the United States.  They found that intermittent explosive disorder is "much more common" than has been recognized.  They say it affects as many as seven percent of adults at some point in their lifetimes, depending on how widely it is defined. 

The study suggests that the condition affects up to sixteen million Americans.  It generally appears around the age of fourteen, and is more common in men than in women. 

Doctors say it usually begins with incidents of extreme anger directed at family members.  They say the problem is made worse for some by stress from bad drivers, long travel times, crowded roads and busy lives.  They say a small traffic problem can cause the person to become uncontrollably angry.

Mental health specialists say the study is important because not many people know about intermittent explosive disorder.  They say the anger can be controlled with medication and therapy.  The findings are published in the Archives of General Psychiatry. 

More than eighty percent of the people with the disorder also had depression, anxiety or problems with drugs or alcohol.  But the researchers say less than thirty percent were ever treated for their anger.  They suggest that early treatment of anger might prevent some of the other disorders.

This VOA Special English Health Report was written by Brianna Blake.  You can find this report online at voaspecialenglish.com.  I’m Steve Ember.