Can Community Social Cohesion Prevent Posttraumatic Stress Disorder in the Aftermath of a Disaster? A Natural Experiment From the 2011 Tohoku Earthquake and Tsunami
In the aftermath of a disaster, the risk of posttraumatic stress disorder (PTSD) is high. We sought to examine whether the predisaster level of community social cohesion was associated with a lower risk of PTSD after the earthquake and tsunami in Tohoku, Japan, on March 11, 2011. The baseline for our natural experiment was established in a survey of older community dwelling adults who lived 80 kilometers west of the epicenter 7 months before the earthquake and tsunami. A follow up survey was conducted approximately 2.5 years after the disaster. We used a spatial Durbin model to examine the association of community level social cohesion with the individual risk of PTSD. Among our analytic sample (n 3,567) 11.4% of respondents reported severe PTSD symptoms. In the spatial Durbin model, individual and community level social cohesion before the disaster were significantly associated with lower risks of PTSD symptoms (odds ratio 0.87, 95% confidence interval: 0.77, 0.98 and odds ratio 0.75, 95% confidence interval: 0.63, 0.90, respectively) even after adjustment for depression symptoms at baseline and experiences during the disaster (including loss of loved ones, housing damage, and interruption of access to health care) Community level social cohesion strengthens the resilience of community residents in the aftermath of a disaster.
American journal of epidemiology