Differences in the determinants of posttraumatic stress disorder and depression after a mass traumatic event.

Background: Hurricane Ike struck the Galveston Bay area of Texas on September 13, 2008, leaving substantial destruction and a number of deaths in its wake. We assessed differences in the determinants of posttraumatic stress disorder (PTSD) and depression after this event, including the particular hurricane experiences, including postevent nontraumatic stressors, that were associated with these pathologies.

Methods: 658 adults who had been living in Galveston and Chambers counties, TX in the month before Hurricane Ike were interviewed 2-5 months after the hurricane. We collected information on experiences during and after Hurricane Ike, PTSD and depressive symptoms in the month before the interview, and socio-demographic characteristics.

Results: The prevalence of past month hurricane-related PTSD and depression was 6.1 and 4.9%, respectively. Hurricane experiences, but not socio-demographic characteristics, were associated with Ike-related PTSD. By contrast, lower education and household income, and more lifetime stressors were associated with depression, as were hurricane exposures and hurricane-related stressors. When looking at specific hurricane-related stressors, loss or damage of sentimental possessions was associated with both PTSD and depression; however, health problems related to Ike were associated only with PTSD, whereas financial loss as a result of the hurricane was associated only with depression.

Conclusions: PTSD is indeed a disorder of event exposure, whereas risk of depression is more clearly driven by personal vulnerability and exposure to stressors. The role of nontraumatic stressors in shaping risk of both pathologies suggests that alleviating stressors after disasters has clear potential to mitigate the psychological sequelae of these events.