PTSD Wears Genes

Post Traumatic Stress Disorder more likely in those with TPH1 and TPH2 gene variants

(RxWiki News) Those who have undergone an extreme and traumatic experience sometimes develop Post Traumatic Stress Disorder (PTSD). But what determines who will and who will not? New findings may hold the key to the answer.

There are two genes, named TPH1 and TPH2, that have recently been linked with PTSD. The genes control production of serotonin, a chemical in the brain.

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"People can develop post-traumatic stress disorder after surviving a life-threatening ordeal like war, rape or a natural disaster," explains Armen Goenjian, M.D., a research professor of psychiatry at the Semel Institute for Neuroscience and Human Behavior at UCLA. "If confirmed, our findings could eventually lead to new ways to screen people at risk for PTSD and target specific medicines for preventing and treating the disorder."

The research team extracted DNA from 200 adults from from 12 extended families. The families all suffered from PTSD after the 1988 Armenian earthquake.

Those who had specific variants of the TPH1 and TPH2 genes were more likely to develop PTSD. The researchers hypothesize that these individuals produce less serotonin, which inhibits their ability to regulate mood, sleep, and alertness.

“We suspect that the gene variants produce less serotonin, predisposing these family members to PTSD after exposure to violence or disaster," says Goenjian. "Our next step will be to try and replicate the findings in a larger, more heterogeneous population."

The researchers are hopeful that this information could help classify the disorder based on biology - as opposed to observation. Currently, treatment for PTSD varies greatly from patient to patient due to lack of formal treatment and diagnosis options.

"A diagnostic tool based upon TPH1 and TPH2 could enable military leaders to identify soldiers who are at higher risk of developing PTSD, and reassign their combat duties accordingly," notes Goenjian. "Our findings may also help scientists uncover alternative treatments for the disorder, such as gene therapy or new drugs that regulate the chemicals responsible for PTSD symptoms."

The study will be published in the April 3 online edition of the Journal of Affective Disorders. Funding for the study was provided by the Collaborative Neuroscience Network. The researchers report no conflicts of interest.

Review Date: 
April 2, 2012