Research from UCLA is showing that the reason some people exhibit post-traumatic stress disorder (PTSD), while others are seemingly able to cope with life threatening situations more easily, is at least in part, down to their genes.
Researchers found that two genes associated with serotonin production lead to a higher risk of the problem. Their article, published in the Journal of Affective Disorders, suggests not only a way of identifying people that may be susceptible to the problem, but also points the way to new and more comprehensive treatments.
Lead author Dr. Armen Goenjian, a research professor of psychiatry at the Semel Institute for Neuroscience and Human Behavior at UCLA continues :
"People can develop post-traumatic stress disorder after surviving a life-threatening ordeal like war, rape or a natural disaster ... 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."
Examples of PTSD include: psychological fallout from a variety of harrowing situation from: child abuse, terrorist attacks, sexual or physical assault, major accidents, natural disasters, or exposure to war or combat. The Vietnam War veterans being the classic example that has been popularized in various movies and TV shows. Afterwards, those affected experience symptoms such as flashbacks, feeling emotionally numb or hyper-alert to danger, as well as trying to avoid scenarios that remind them of the trauma.
Goenjian analyzed DNA from 200 adults from Armenia who survived the devastating 1988 earthquake. The people spanned several generations and were from 12 extended families who suffered PTSD symptoms after the disaster. The families' genes showed that those who had specific variants of two genes were more prone to PTSD symptoms. The genes, called TPH1 and TPH2, control the production of serotonin. Serotonin is a brain chemical that regulates mood, sleep and alertness, all of these are disrupted in PTSD. Serotonin problems have been shown to be responsible in some mental health problems, and are also associated with the effects that opiate based drugs, such as morphine, have on a person.
Goenjian continues that :
"We suspect that the gene variants produce less serotonin, predisposing these family members to PTSD after exposure to violence or disaster ... Our next step will be to try and replicate the findings in a larger, more heterogeneous population ... 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 ... 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."
PTSD has become more of an issue with the Iraq and Afgan wars which are still ongoing, and troops being exposed to similar dire attacks, roadside bombings and other unexpected traumas. The UCLA's work could be used not only to help treat people, but also to avoid putting those that are more prone to the problem into situations that are likely to cause them long-term problems.
Until now, psychiatrists have relied more or less on trial and error and past experience to treat patients. In the future, they should be able to pinpoint a patient's problems more accurately.
Serotonin is the target of the popular antidepressants known as SSRIs, or selective serotonin re-uptake inhibitors, which prolong the effect of serotonin in the brain by slowing its absorption by brain cells. More physicians are prescribing SSRIs to treat psychiatric disease beyond depression, including PTSD and obsessive-compulsive disorder.
Written by Rupert Shepherd