95 Views   no discussions Share Sharing is caring! CNN News Share Tweet After a single traumatic event, as many as one-fourth of people exposed will develop post-traumatic stress disorder, a psychiatric disorder characterized by anxiety, hyperarousal and persistent unwanted memories.Scientists are looking for genes or gene pathways that can help better predict PTSD. A new study in the journal Nature suggests one such route in women: through a protein called pituitary adenylate cyclase-activating polypeptide, which is known to regulate the cellular stress response. Women are more likely to have PTSD in general; 10% of women and 5% of men develop the condition sometime in their lives.Participants, of which there were more than 1,200, came from an impoverished area around Atlanta, Georgia, and did not have military-related trauma. Interpersonal violence, gunshot violence, sexual assaults and other abuse were some of the triggers of PTSD reported.Study results suggest that a particular gene variant for PACAP may be sensitive to both estrogen and stress, because it is associated with women who have PTSD.“It helps us to understand that PTSD is complex,” said Dr. Kerry Ressler of Emory University School of Medicine, lead study author. “There are many individual ways that people come to PTSD, in the same way that there are probably 100 different ways to come down with heart failure.”This is probably one of many biological pathways that lead to PTSD, he said. Understanding it will help get a better picture of the biology and the neural circuitry of PTSD, and could have implications for future diagnosis and treatment of the condition.Ressler’s group found that this gene variant is highly associated with all three subcategories of PTSD: hyperarousal, intrusive memories and avoidant behavior. It could be broadly linked to all of them, or perhaps the definition of PTSD is not specific enough to what’s going on biologically, Ressler said.In rodents, the parts of the brain associated with fear and stress alter the regulation of these genes with fear learning. This could be happening in humans also, he said.The gene variant described in the research influences the key human stress response system, which is central to PTSD and so it makes clinical sense that it would be involved, said Dr. John Markowitz, PTSD researcher at Columbia University College of Physicians and Surgeons, who is not a geneticist but offered his clinical perspective on the research.But, Markowitz cautioned, in an e-mail, “the history of psychiatric genetics is littered with findings subsequently retracted or not borne out.” This particular study, which he called an “elegant research report,” has results that apply only to an estrogen gene in chronically traumatized women.There is more work to be done to examine the roots of PTSD in men, and there may be other pathways involved in women with acute trauma, Markowitz said. Another next step would be to examine whether the results of this study are consistent in members of the military. Share HealthLifestyle PTSD in women may have genetic link by: – February 25, 2011 read more