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VA Research Currents archive
Posted December 3, 2013
Women with a specific genetic variant are less likely to suffer the effects of posttraumatic stress disorder, according to a new VA study.
Women with a variant of a gene called CRHR-2, involved in the body's response to threats, could be at reduced risk for PTSD following a trauma, suggests a study by VA researchers in Boston. (U.S. Marine photo by Sgt. James R. Richardson)
Researchers already knew that the corticotropin releasing hormone (CRH) system is associated with anxiety and mood-based disorders and plays a role in the biological response to threat. Now a study of 491 trauma-exposed Veterans and their intimate partners has revealed that women with a variant of a gene, called CRHR-2, involved in regulating the CRH system may experience reduced symptoms of PTSD following trauma exposure. The research could lead to new ways of preventing and treating trauma disorders.
Genetic variation could explain why only a subset of those exposed to trauma ever develop the disorder. Some 50 to 90 percent of the general population experience trauma in their lives, yet only 8 to 14 percent ever develop PTSD. "This suggests that individual differences in biological risk may increase or decrease the likelihood of PTSD," wrote the study authors, led by Dr. Erika Wolf and principal investigator Dr. Mark Miller, of the National Center for PTSD at VA Boston Healthcare System and Boston University School of Medicine.
Wolf and colleagues looked at 491 Caucasian participants between 21 and 75 years old who reported traumatic exposure. Sixty-five percent of the participants were males and just over 60 percent met criteria for a diagnosis of PTSD at some point in their lifetime.
For the study, researchers recruited Veterans via fliers, phone calls, and clinical referrals and then conducted videotaped interviews to determine if individuals met criteria for PTSD and other mental health diagnoses. Participants were then asked to provide a blood sample that was genotyped to examine genetic variation across the genome, including in the CRHR-2 gene.
The researchers found several locations within the CRHR-2 gene that were associated with reduced risk of PTSD and reduced severity of PTSD symptoms. These associations did not vary across individuals with different levels of trauma but did differ across men and women in that the effect was more pronounced among the women in the sample. "The findings provide initial evidence that the relationship of the CRHR-2 genotype to PTSD may be specific to women," wrote the authors. The study is the first of its kind to look at how this CRH variant and trauma affect risk for PTSD.