The Washington Post (4/1, A4, Brown) reported, “Numerous studies have shown that repeated deployment is a ‘risk factor’ for” post-traumatic stress disorder (PTSD). For example, a study published in the March issue of the American Journal of Public Health “examined the experience of 66,000 Marines who served in Iraq. Those with two deployments had almost twice the rate of PTSD as those deployed once.”
PTSD Susceptibility May Be Partially Determined By Gene Variants. BBC News (4/2) reports, “Susceptibility to post-traumatic stress disorder (PTSD) could be partially determined by gene variants,” according to a study published in the Journal of Affective Disorders. After examining “DNA from 200 members of 12 families who survived the 1988 Armenian earthquake,” researchers found that “those who carried two gene variants which affect the production of serotonin — which affects mood and behaviour — were more likely to display symptoms of PTSD.”
— “Link between PTSD and violent behavior is weak,”David Brown, The Washington Post, March 31, 2012.