THE VIRGINIAN-PILOT
Copyright (c) 1996, Landmark Communications, Inc.
DATE: Wednesday, May 8, 1996 TAG: 9605080438
SECTION: FRONT PAGE: A8 EDITION: FINAL
SOURCE: ASSOCIATED PRESS
DATELINE: NEW YORK LENGTH: Short : 45 lines
Yielding a possible clue to what causes post-traumatic stress disorder, a study of Vietnam veterans found that a particular brain structure was smaller in men with more combat exposure.
The size difference was seen in the hippocampus, a part of the brain involved in memory and some other functions.
It might be involved in suppressing emotional reactions to traumatic experiences, said Dr. Roger Pitman. An impairment in the hippocampus might explain why people with post-traumatic stress disorder can be overwhelmed by memories of stressful events, he said.
Pitman, a researcher at the Veterans Affairs Medical Center in Manchester, N.H., and Harvard Medical School, described the study Tuesday at a news conference at the annual meeting of the American Psychiatric Association.
PTSD is caused by exposure to extremely stressful situations. Symptoms can include flashbacks, recurring dreams of the event, difficulty concentrating and angry outbursts.
The study used brain scans to compare the size of the hippocampus in seven Vietnam veterans with PTSD and seven others without it. The degree of exposure to combat was measured by a standard scale that included such factors as how often a person was fired at, saw a buddy killed, was in danger and had other wartime experiences.
The study found that the higher the combat exposure, the smaller the combined volume of the two hippocampi in the brain. Veterans with PTSD, as a group, had smaller hippocampal volumes than the other veterans.
Animal studies also suggest that stress can damage the hippocampus. But Pitman stressed that the new study shows only a statistical relationship and does not prove that combat stress shrank the hippocampus.
If stress does have that effect, perhaps drugs can be found that will reverse the effect and become a new treatment for PTSD, he said. Or drugs taken right after the stressful event might be able to prevent the hippocampal damage, he said. by CNB