A study recently published in the Proceedings of the National Academy of Sciences claims to have found a link between a specific gene and the development of PTSD. The abstract of the study reads:
Strong memory of a traumatic event is thought to contribute to the development and symptoms of posttraumatic stress disorder (PTSD). Therefore, a genetic predisposition to build strong memories could lead to increased risk for PTSD after a traumatic event. Here we show that genetic variability of the gene encoding PKCα (PRKCA) was associated with memory capacity—including aversive memory—in nontraumatized subjects of European descent. This finding was replicated in an independent sample of nontraumatized subjects, who additionally underwent functional magnetic resonance imaging (fMRI). fMRI analysis revealed PRKCA genotype-dependent brain activation differences during successful encoding of aversive information. Further, the identified genetic variant was also related to traumatic memory and to the risk for PTSD in heavily traumatized survivors of the Rwandan genocide. Our results indicate a role for PKCα in memory and suggest a genetic link between memory and the risk for PTSD.
This could very well be the reason behind why two soldiers can experience the same event but only one goes on to develop PTSD. However, this could also effect the discussion on changing the name from Post Traumatic Stress Disorder to Injury. Webster’s defines ‘Disorder’ as:
1: to disturb the order of
2: to disturb the regular or normal functions of
I could see having both titles in the Diagnostic and Statistical Manual of Mental Disorders. The immediate and acute phase being the injury. Post Traumatic Stress IS an injury. It is something inflicted upon a person and therefore fits the definition of ‘injury’. However, the fact that it has been shown to fundamentally change the way the brain functions, ‘disorder’ is also more than appropriate, especially in chronic cases of PTSD.
There are many gene variants that have no adverse effect on the human body until they are triggered by an external stimuli (even when that stimuli is undefined). For example, it is thought that Celiac Disease may be genetically transmitted, though it is unknown why it effects one member of the family and not others, or doesn’t effect them until later in life. The trigger isn’t identifiable but it can still be shown that a person had no issue with gluten while growing yet a sibling has issues from a very young age. Another example is Sicle Cell Anemia. Originally, this mutation occurred as an adaptation to combat Malaria. Today, such an adaptation is more of a medical problem than a benefit. You can see entire families with the gene yet not every member will experience a crisis. The same may very well be true of PTSD.
Locating PTSD’s genetic source could open the door to more effective treatments such as gene therapy. Such an approach may not erase PTSD once its begun but could perhaps help to avoid future traumas from worsening the symptoms of PTSD. At this point, its all conjecture, but it is promising nonetheless.