Study IDs two genes that boost risk for post-traumatic stress disorder

A discovery by UCLA researchers may answer the question of why some people develop post-traumatic stress disorder (PTSD) while others who suffered the same ordeal do not. UCLA scientists have linked two gene variants to the debilitating mental disorder, suggesting that heredity influences a person’s risk of developing PTSD. The findings, published in the Journal of Affective Disorders, could provide a biological basis for diagnosing and treating PTSD more effectively.

In 1988, a 6.8 magnitude earthquake devastated the country of Armenia. The temblor leveled entire towns and cities, killing more than 25,000 Armenians, two-thirds of them children. With support from the Armenian Relief Society, UCLA researchers helped establish two psychiatric clinics that treated earthquake survivors for 21 years. A dozen multigenerational families in northern Armenia agreed to allow their blood samples to be sent to UCLA, where the team combed the DNA of 200 individuals for genetic clues to psychiatric vulnerability.

Researchers discovered that PTSD was more common in survivors who carried two gene variants associated with depression. In the current study, they focused on two genes, COMT and TPH-2, which play important roles in brain function. COMT is an enzyme that degrades dopamine, a neurotransmitter that controls the brain’s reward and pleasure centers, and helps regulate mood, thinking, attention, and behavior. Too much or too little dopamine can influence various neurological and psychological disorders. TPH-2 controls the production of serotonin, a brain hormone that regulates mood, sleep, and alertness—all of which are disrupted in PTSD.