In what is a first study of this type, researchers in the UCLA Department of Psychiatry and Biobehavioral Sciences concluded that post-traumatic stress is not only an isolated phenomenon, but can run in families as well, if these have been through a traumatic experience. While the heritability of PTSD was suspected before, this recent research comes to prove that, for one, earthquake victims are just like war veterans and, moreover, that their symptoms can be passed on to their children.

The study was performed on 200 participants from 12 multigenerational families exposed to the 1988 earthquake in Armenia. Killing 17,000 people and destroying almost half of the town of Gumri, the study has clearly revealed that the natural catastrophe still resounds in the minds of both survivors and their offspring.

"This was a study of multigenerational family members - parents and offspring, grandparents and grandchildren, siblings, and so on - and we found that the genetic makeup of some of these individuals renders them more vulnerable to develop PTSD, anxiety and depressive symptoms," Armen Goenjian, member of the UCLA-Duke University National Center for Child Traumatic Stress and lead author of the study, said.

Researches discovered that, in all 200 participants, 41 percent of the variation of PTSD symptoms was explainable by genetics, as also were 61 percent of that of depressive symptoms and 66 percent of anxiety symptoms. The study also revealed that a large percentage of the genetic liabilities for these specific disorders were shared among family members.

“That tracks with clinical experience. For example, in clinical practice, the therapist will often discover that patients who come in for treatment of depression have coexisting anxiety. Our findings show that a substantial portion of the coexistence can be explained on the basis of shared genes and not just environmental factors such as upbringing,” Dr. Goenjian added, explaining that a large percentage of genes are also shared between the disorders.