Study suggests some brain injuries reduce the likelihood of post-traumatic stress disorderDecember 26, 2007A new study of combat-exposed Vietnam War veterans shows that those with injuries to certain parts of the brain were less likely to develop post-traumatic stress disorder (PTSD). The findings, from the National Institutes of Health (NIH) and the National Naval Medical Center, suggest that drugs or pacemaker-like devices aimed at dampening activity in these brain regions might be effective treatments for PTSD. PTSD involves the persistent reliving of a traumatic experience through nightmares and flashbacks that may seem real. Twenty percent to 30 percent of Vietnam vets (more than 1 million) have been diagnosed with PTSD, and a similar rate has been reported among Hurricane Katrina survivors in New Orleans. Public health officials are currently tracking the disorder among soldiers returning from Iraq. Yet, while war and natural disasters tend to call the greatest attention to PTSD, it's estimated that millions of Americans suffer from it as a result of assault, rape, child abuse, car accidents, and other traumatic events. Previous studies have shown that PTSD is associated with changes in brain activity, but those studies couldn't determine whether the changes were contributing to the disorder or merely occurring because of it. Jordan Grafman, Ph.D., a senior investigator at the National Institute of Neurological Disorders and Stroke (NINDS), part of NIH, turned to the Vietnam Head Injury Study (VHIS) to make that distinction. The VHIS is a registry of Vietnam veterans who sustained penetrating brain injuries (which are less common in Iraq compared to concussion brain injuries). It has received support from the Department of Defense, the Department of Veterans of Affairs and NIH, and is currently supported by NINDS. "If we could show that lesions in a specific brain region eliminated PTSD, we knew we could say that the region is critical to developing the disorder," says Dr. Grafman. The results of his study appear online today in Nature Neuroscience. Dr. Grafman and members of his lab, including neuropsychiatrist Vanessa Raymont and postdoctoral fellow Michael Koenigs, studied 193 veterans registered with VHIS and 52 veterans with combat exposure but no head injury. The participants were classified as either having developed PTSD at some point in their lifetime or having never developed PTSD. CT (computerized tomography) scans were used to map their brain injuries. By comparing the distribution of brain injuries between the PTSD group and the non-PTSD group, the researchers found two regions where damage was rarely associated with PTSD: the amygdala, a structure important in fear and anxiety, and the ventromedial prefrontal cortex (vmPFC), an area involved in higher mental functions and planning. In another level of analysis, the researchers compared the prevalence of PTSD in subjects who had damage to either the amygdala or vmPFC, subjects who had damage to other parts of the brain and non-head-injured subjects. PTSD occurred in a similar fraction of subjects in the last two groups - 40 percent and 48 percent, respectively. In contrast, PTSD occurred in only 18 percent of subjects with damage to the vmPFC and zero (out of 50) subjects with damage to the amygdala. The occurrence of other anxiety disorders was not affected by damage to the amygdala or vmPFC. "It appears that if you have damage to either of those areas, you're not likely to develop PTSD," says Dr. Grafman. The scientists hypothesize that drugs designed to inhibit the activity of the two structures might provide relief from PTSD. Deep brain stimulation, a technique used to treat Parkinson's disease by modifying the brain's electrical activity, might also prove useful against PTSD if targeted to the amygdala or vmPFC. Current treatments for PTSD include medications for anxiety and depression, and therapy to help the person confront and deal with traumatic memories. But these treatments vary in effectiveness, a point underscored by the fact that many of the Vietnam veterans in Dr. Grafman's study are still dealing with PTSD some 40 years after the war. Since the study examined only young men who served in Vietnam, one question is whether the results will extend to women, children, or people exposed to traumatic situations besides wartime combat. Dr. Grafman says similar results probably will be found in those other populations, given that previous studies had connected PTSD to changes in the amygdala and vmPFC, and only some of those studies involved war veterans. NIH/National Institute of Neurological Disorders and Stroke |
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| Related Post-traumatic Stress Disorder Current Events and Post-traumatic Stress Disorder News Articles New UAB Study Sheds Light on Brain's Response to Distress, Unexpected Events In a new study, psychologists at the University of Alabama at Birmingham (UAB) are able to see in detail for the first time how various regions of the human brain respond when people experience an unexpected or traumatic event. Psychiatric impact of torture could be amplified by head injury Depression and other emotional symptoms in survivors of torture and other traumatic experiences may be exacerbated by the effects of head injuries, according to a study from the Harvard Program in Refugee Trauma (HPRT), based in the Massachusetts General Hospital (MGH) Department of Psychiatry. Use of cannabinoids (marijuana) could help post-traumatic stress disorder patients Use of cannabinoids (marijuana) could assist in the treatment of post-traumatic stress disorder patients. This is exposed in a new study carried out at the Learning and Memory Lab in the University of Haifa's Department of Psychology. MU Researchers Use Computational Models to Study Fear The brain is a complex system made of billions of neurons and thousands of connections that relate to every human feeling, including one of the strongest emotions, fear. Researchers unravel mystery behind long-lasting memories A new study by researchers at Wake Forest University School of Medicine may reveal how long-lasting memories form in the brain. PTSD associated with higher Alzheimer's/dementia risk; moderate alcohol consumption may lower it Though discoveries about Alzheimer's disease risk factors are often in the news, adults do not know about the relationship between Alzheimer's disease risk and heart health, nor that physical activity can be protective against dementia. Neuroscience research could benefit US Army, yet challenge traditional approaches Advances in neuroscience research could benefit the Army, particularly in areas of soldier training and education. However, an emerging trend of using individual variability in neural processes such as cognition, stress response, and decision making to improve group performance is likely to challenge conventional approaches to training and educating soldiers. Witnessing violence affects kids' health School-aged children who witness violence in urban communities show symptoms of post-traumatic stress. They also suffer physiological effects with a disruption to their normal cortisol production pattern during the day, which may have long-term negative effects on their health. Controlling our brain's perception of emotional events Research performed by Nicole Lauzon and Dr. Steven Laviolette of the Schulich School of Medicine & Dentistry at The University of Western Ontario has found key processes in the brain that control the emotional significance of our experiences and how we form memories of them. Researchers reveal how the brain processes important information Researchers at UT Southwestern Medical Center have shed light on how the neurotransmitter dopamine helps brain cells process important information. More Post-traumatic Stress Disorder Current Events and Post-traumatic Stress Disorder News Articles |
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