The Neurobiology of Fear: Emotional Memory and Post-Traumatic Stress Di

The Neurobiology of Fear: Emotional Memory and Post-Traumatic Stress Disorder For survivors of traumatic events, the trauma itself is often only the beginning. While some are relatively unaffected, many others will develop post-traumatic stress disorder, or PTSD, an affliction that haunts its victims with terrifying memories, nightmares, and panic attacks. (For a comprehensive list of symptoms and diagnostic criteria, the reader may refer to the DSM-IV, relevant portions of which may be found online (7).) The National Institute of Mental Health estimates that 3.6 percent of Americans between the ages of 18 and 54 suffer from PTSD; 30 percent of those who have spent time in war zones - one million veterans of Vietnam alone - are affected (6). PTSD is treated with several forms of psychotherapy, including exposure therapy, centered around a controlled confrontation of frightening stimuli. While medication may treat co-occurring depression, anxiety, or insomnia (6), pharmacological agents targeting PTSD remain unavailable. In part, this is because researchers hav e only begun to describe the underlying neurobiology. Several recent studies have pointed to the brain structure known as the amygdala as a central player, but questions remain: How does this small structure "recognize" danger? How does it create emotional memories? What causes recurrence of these memories? Answers to these questions are complex and incomplete. As an anxiety disorder, PTSD has its foundations in fear and "emotional memory." Like factual memory, emotional memory also involves the storage and recall of events and details; this has been termed the explicit or conscious memory (2). Emotional memory, though, has a second, distinct component. This facet, t... ...ing, from Stephen Maren's Emotion and Memory Systems Laboratory at the University of Michigan. http://maren1.psych.lsa.umich.edu/Models.html 4)Summary of Research at Stephen Maren's Emotion and Memory Systems Laboratory at the University of Michigan. http://maren1.psych.lsa.umich.edu/Research.html 5)Anxiety Disorders Treatment Target: Amygdala Circuitry, from the National Institute of Mental Health. http://www.nimh.nih.gov/events/pranxst.cfm 6)Facts About Post-Traumatic Stress Disorder, from the National Institute of Mental Health. http://www.nimh.nih.gov/anxiety/ptsdfacts.cfm 7)PTSD Diagnostic Criteria from the DSM-IV, from Bully Online, a service of the United Kingdom National Workplace Bullying Advice Line. http://www.successunlimited.co.uk/PTSD/ 8)Building a Brainier Mouse. Zsien, Joe T. 2000. Scientific American http://www.sciam.com/missing.cfm