Increased frequency of participation in civic associations and reduced depressive symptoms: Prospective study of older Japanese survivors of the Great Eastern Japan Earthquake.

Abstract

Few studies have examined whether changes in participation in civic associations can mitigate depressive symptoms among older disaster survivors. We examined prospectively the association between changes in participation in civic associations and changes in depressive symptoms among older survivors of the 2011 Great Eastern Japan Earthquake. We analyzed questionnaire-based survey data on pre- and post-disaster participation in civic associations and depressive symptoms compiled for 3567 respondents aged 65 years and above. Changes in these symptoms were assessed using a 15-item Geriatric Depression Scale (GDS) as a continuous variable for 2010 and 2013. We investigated four types of civic associations: sports, hobby, voluntary groups, and senior citizens' clubs. Changes in participation were calculated by subtracting the participation frequency measured in 2010 from that measured in 2013. Applying 95% confidence intervals, we used linear regression models with imputation to estimate the age- and sex-adjusted and multivariate-adjusted standardized coefficients. The survivors' GDS scores increased by 0.13 points on average between the pre-disaster and post-disaster periods. Average changes in the participation frequencies of respondents in each group were respectively +0.36 days/year, -5.63 days/year, +0.51 days/year, and -1.45 days/year. Increased frequencies of participation in the sports and hobby groups were inversely associated with changes in GDS scores (B=-0.003, Cohen's f2=0.10, P=0.01 and B=-0.002, Cohen's f2=0.08, P=0.04, respectively). The associations did not differ depending on the experience of housing damage caused by the disaster. In addition, we did not observe a significant association between changes in participation frequencies for voluntary groups or senior citizens' clubs and changes in GDS scores after multivariable adjustment. Depressive symptoms of older adults post-disaster may be mitigated through increased frequency of participation in sports and hobby groups; yet, civic participation did not mitigate the adverse impact of disaster experiences on mental health.