To you, that angry, horn-blasting tailgater is suffering from road rage. But doctors have another name for it — intermittent explosive disorder — and a new study suggests it is far more common than they realized, affecting up to 16 million Americans.

“People think it’s bad behavior and that you just need an attitude adjustment, but what they don’t know ... is that there’s a biology and cognitive science to this,” said Dr. Emil Coccaro, chairman of psychiatry at the University of Chicago’s medical school.

Road rage, temper outbursts that involve throwing or breaking objects and even spousal abuse can sometimes be attributed to the disorder, though not everyone who does those things is afflicted.

Multiple angry outbursts
By definition, intermittent explosive disorder involves multiple outbursts that are way out of proportion to the situation. These angry outbursts often include threats or aggressive actions and property damage. The disorder typically first appears in adolescence; in the study, the average age of onset was 14.

The study was based on a national face-to-face survey of 9,282 U.S. adults who answered diagnostic questionnaires in 2001-03. It was funded by the National Institute of Mental Health.

About 5 percent to 7 percent of the nationally representative sample had had the disorder, which would equal up to 16 million Americans. That is higher than better-known mental illnesses such as schizophrenia and bipolar disorder, Coccaro said.

The average number of lifetime attacks per person was 43, resulting in $1,359 in property damage per person. About 4 percent had suffered recent attacks.

The findings were released Monday in the June issue of the Archives of General Psychiatry.

Disorder more common than thought
The findings show the little-studied disorder is much more common than previously thought, said lead author Ronald Kessler, a health care policy professor at Harvard Medical School.

“It is news to a lot of people even who are specialists in mental health services that such a large proportion of the population has these clinically significant anger attacks,” Kessler said.

Four a couple of decades, intermittent explosive disorder, or IED, has been included in the manual psychiatrists use to diagnose mental illness, though with slightly different names and criteria. That has contributed to misunderstanding and underappreciation of the disorder, said Coccaro, a study co-author.

Coccaro said the disorder involves inadequate production or functioning of serotonin, a mood-regulating and behavior-inhibiting brain chemical. Treatment with antidepressants, including those that target serotonin receptors in the brain, is often helpful, along with behavior therapy akin to anger management, Coccaro said.

Symptoms often appear in childhood
Most sufferers in the study had other emotional disorders or drug or alcohol problems and had gotten treatment for them, but only 28 percent had ever received treatment for anger.

“This is a well-designed, large-scale, face-to-face study with interesting and useful results,” said Dr. David Fassler, a psychiatry professor at the University of Vermont. “The findings also confirm that for most people, the difficulties associated with the disorder begin during childhood or adolescence, and they often have a profound and ongoing impact on the person’s life.”

Jennifer Hartstein, a psychologist at Montefiore Medical Center in New York, said she had just diagnosed the disorder in a 16-year-old boy.

“In most situations, he is relatively affable, calm and very responsible,” she said. But in stressful situations at home, he “explodes and tears apart his room, throws things at other people” to the point that his parents have called the police.

Hartstein said the study is important because many people are not aware of the disorder.

© 2006 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Arnold-Chiari

Arnold-Chiari Malformation, is characterized by a small or misshapen posterior fossa (the depression in the back of the skull), a reduction in cerebrospinal fluid pathways and a protrusion of the cerebellar tonsils through the bottom of the skull (foramen magnum) into the spinal canal resulting in a multitude of sensory-motor problems and even some autonomous malfunctions (1).

These many symptoms can come in a variety of forms which often makes a clinical diagnosis difficult. To the patient this disorder can present not only physical difficulties but also mental distress. Treatment options and their success rates vary widely, and proponents of the cause are demanding more recognition, research, and success. The study of Arnold-Chiari malformations can lead to additional questions and new understandings about the I-function, sensory-motor input/output paths and the general make-up of the brain and nervous system, but a complete understanding of the disorder may be a long time coming. Impairment and sometimes loss of motor control of the body and its extremities is one of the many effects of this disorder. Patients may complain of headaches, neck pain, coughing, sneezing, dizziness, vertigo, disequilibrium, muscle weakness, balance problems, and loss of fine motor control. The senses (hearing, sight, smell etc.) may also be affected in deleterious ways. On can have blurred vision, decreased sensation of limbs, unable to locate them without looking, decreased sense of taste, ringing of the ears etc.

Two ideas about the nervous system that can be better understood from these observations are the concepts of having and locating the I-function. It seems that the I-function here is very often affected in terms of voluntary movement. A person with Arnold-Chiari malformation who has lost the feeling in and control of his arm for example will not be able to move it even upon someone's request and his or her own desire to do so. Some use of the I-function is definitely impaired. However, these observations do not seem to necessarily imply that some part of the I-function was damaged, because it may very well be located elsewhere- connections may have simply been lost. A person with Arnold-Chiari can still think and have a sense of self, but somehow can not connect with the various body parts that can be affected. Some uses and pathways of the I-function can be understood, but the exact location of it remains vague.

A lack of sensory input can also provide clues about pathways within the nervous system. Depending on the severity and specific location of the Chiari malformation different senses may be affected. Again, the location of where this information is processed can not be determined for sure from these observations alone. It is obvious that the pathway needed for sensory information to travel is indeed affected but not the ultimate processing center itself. Recently, diagnosing this disorder has become relatively easier with the advent of the MRI (magnetic resonance imaging)...

i have had three in my life just because of this "malformation"

...so that doctors and patients no longer have to rely on a symptom-based diagnosis which was troublesome for both. The symptoms vary widely and encompass many parts of the body. Many deemed Arnold-Chiari sufferers the victims of some psychosomatic disease before the biological nature of the disorder was understood. Now, with the possibility of having a genetic predisposition for Chiari and the early detection devices available, one can more easily be diagnosed properly.

There are both medical and non-medical ways to treat Arnold-Chiari malformations. When symptoms develop, patients should seek a doctor's advice to consider a posterior fossa and upper cervical decompression. This procedure can provide more room around the lower brainstem and promotes improved neurologic functioning, though it is not a guaranteed solution. Patients may also benefit from various and symptom appropriate forms of physical and occupational therapy. Some patients also explore non-traditional options such as herbal therapy, acupuncture and others.

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