Using genetic variations to predict posttraumatic stress disorder symptoms


Using genetic variations to predict posttraumatic stress disorder symptoms


A study published in JAMA reports that adults are more likely to have posttraumatic stress disorder symptoms if they have been abused as a child and have variations of a gene that is related to stress response. The investigation was conducted by Rebekah G. Bradley, Ph.D. (Emory University School of Medicine, Atlanta) and colleagues.

Providing background information, the authors write: "Posttraumatic stress disorder (PTSD) is a debilitating stress-related psychiatric disorder, with prevalence rates of at least 7 percent to 8 percent in the U.S. population, and with much higher rates among combat veterans and those living in high-violence areas. Initially viewed as a potentially normative response to traumatic exposure, it became clear that not everyone experiencing trauma develops PTSD. Thus, a central question in research on PTSD is why some individuals are more likely than others to develop the disorder in the face of similar levels of trauma exposure."

Recent research has suggested that the psychological risk to the traumatized individual is due to both genetic and environmental factors, and child abuse is predicted to significantly increase the risk of developing PTSD.

Dr. Bradley and colleagues set out to investigate how polymorphisms (gene variations) of the gene FKBP5 predict PTSD symptoms in highly traumatized, low-income men and women who live in an urban area. FKBP5 is one of the genes related to stress response, and the researchers were interested in predicting adulthood PTSD symptoms by analyzing whether the FKBP5 polymorphisms interacted with increasing levels of both child abuse and other types of trauma exposure.

The sample consisted of 900 general medical clinical patients who had significant levels of child abuse and other types of traumatic experiences. The researchers examined genetic and psychological risk factors using a survey and genetic testing (single-nucleotide polymorphism [SNP] genotyping). Study participants were low-income black men and women who lived in urban areas during 2005 and 2007. They were seeking care in the general medical or OB/GYN clinics of an urban public hospital.

Bradley and colleagues found that adult PTSD symptoms could be independently predicted by the level of child abuse and level of other types of trauma. The genetic analysis found that the variations of FKBP5 did not directly predict PTSD symptoms or predict PTSD symptom severity when interacted with levels of non-child abuse trauma. However, the researchers were able to predict adulthood PTSD symptoms by using four genetic variations in the FKBP5 locus (where the gene is on its chromosome) that did significantly interact with the severity of child abuse. After controlling for depression severity scores, age, sex, levels of non-child-abuse trauma, and genetic ancestry, the gene-environment interaction was still significant.

"The most novel and important finding of our study was the interaction between FKBP5 polymorphisms and child abuse history to predict the levels of adult PTSD symptoms," conclude the authors. "These genotypes potentially serve as predictors of both risk and resilience for adult PTSD among survivors of child physical and sexual abuse."

Association of FKBP5 Polymorphisms and Childhood Abuse With Risk of Posttraumatic Stress Disorder Symptoms in Adults

Elisabeth B. Binder, MD, PhD; Rebekah G. Bradley, PhD; Wei Liu, PhD; Michael P. Epstein, PhD; Todd C. Deveau, BS; Kristina B. Mercer, MPH; Yilang Tang, MD, PhD; Charles F. Gillespie, MD, PhD; Christine M. Heim, PhD; Charles B. Nemeroff, MD, PhD; Ann C. Schwartz, MD; Joseph F. Cubells, MD, PhD; Kerry J. Ressler, MD, PhD

JAMA. 299[11]:1291-1305.

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Psychological Disorders: Crash Course Psychology #28 (Video Medical And Professional 2018).

Section Issues On Medicine: Psychiatry