Intermittent Explosive Disorder

Intermittent Explosive Disorder

Political commentator John McLaughlin introduced the issue on his weekly television program, The McLaughlin Group, like this:

“Road rage drivers are not just angry. They’re crazy. So says research from Harvard and from the University of Chicago. The new sickness is called intermittent explosive disorder or IED. IED sufferers have abnormal areas of the brain that are supposed to control anger. “

The panelists then exchanged some amused banter.

What Is Intermittent Explosive Disorder?

A person with IED is not really crazy. IED is a disorder of impulse control. This means that an individual has difficulty resisting aggressive urges. This results in angry outbursts and destructive behavior that is out of proportion to the situation. A person with IED might assault another person or damage property.

This disorder has come to the attention of news media recently because of a June, 2006 article in the Archives of General Psychiatry, quoted in the McLaughlin program. Researchers from Harvard and the University of Chicago surveyed thousands of people and found that IED was more common than previously thought: More than 7% of the people had responded to situations with uncontrollable anger at some point in their life. (This means that IED affects as many as 16 million Americans.) Almost three-quarters of those had a history of attacking people when they were angry. They also found that the disorder starts early — around age 14 — in many cases starting before any other psychiatric problem becomes apparent.

Violence Is Common

These new data remind us how widespread violence is. IED doesn’t affect any one cultural or socioeconomic group more than another, although younger people are more susceptible than older people. Also there are a wide variety of causes and consequences, with genetics (heredity) and environmental factors contributing equally.

More than 80% of the people surveyed had experienced at least one other psychiatric disorders that fell into one of the following categories:

  • Personality disorders (antisocial or borderline personality disorder)
  • Mood disorders (major depression, bipolar disorder)
  • Anxiety disorders (panic disorder, post-traumatic stress disorder)
  • Psychotic disorders (schizophrenia)
  • Substance abuse (alcohol, drugs)
  • Other medical illnesses (dementia).

Most people with IED in this study did get mental health treatment at some point, but it was rarely specifically for their anger. If anger had become a focus of treatment early on, experts speculate, perhaps their later psychiatric troubles could have been prevented, or at least reduced.

The Biology of Violence

The study of aggression and violent behavior can help us understand IED. Since all behavior — including criminal behavior — originates in the brain, neuroscientists have focused on studying the biology behind violence.

This has taught us that:

  • The ups and downs of stress hormones influence aggressiveness. In people who are quick to feel threatened or frightened, stress hormone levels may rise rapidly. In this state of hyperarousal, adrenaline pumps, heart rate goes up, and the body is ready to fight. The violent outbursts of IED — “road rage” or domestic violence — may follow this biological pattern. This process may also occur in borderline personality disorder or depression.
  • Many violent criminals actually have reduced stress responses, called hypoarousal by scientists doing this research. They have much lower than average emotional barriers to committing violence. Often cold-blooded, their violent behavior may be more premeditated rather than flaring up in response to provocation.
  • Some people with brain injuries become aggressive, especially if the frontal or temporal lobes of the brain are damaged. These regions control impulses and regulate emotion.
  • Similar brain problems may explain the aggressiveness seen in Alzheimer’s disease and other forms of dementia.
  • Aggression and violence sometimes arise in connection with a symptom, such as paranoid delusions in schizophrenia or the irritability of mania.
  • Substances like alcohol can lead to violence by changing the brain regions that control emotion and impulses, or by triggering a hyperarousal state.

As scientists learn more about these mechanisms, they may more accurately define the nature of violence. With a better understanding of what causes the biology to go wrong, treatment will probably also improve and go beyond simplistic prescriptions such as “anger management.”

An Opportunity for Early Treatment

There are two key messages that come out of this new research:

  • Clinicians would be wise to understand violence as a condition that needs treatment even when no other symptoms are obvious.
  • Since violence is often the first symptom to appear, treating it early may help avoid later problems such as the destructive consequences of violence and the psychiatric disorders that may develop.

Significant violence should be treated as a medical problem like chest pain. Clinicians should look for underlying brain disease or injury, mood or psychotic disorders, personality disorders or substance abuse. Treating those illnesses can make an enormous difference and reduce risk.

For people who have the “pure form” of intermittent explosive disorder, where no other mental disorders are found, the serotonin-boosting antidepressants (like Prozac and Zoloft) may reduce irritability and lengthen a short fuse.

Recognizing violence as a treatable problem can and should lead an individual to take more responsibility for violent actions rather than less. Dismissing the problem not only deprives people of help, but also deprives all of us of the chance to reduce violence. As we gain a better understanding through science of how people lose control, we may laugh at them less and help them more.

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