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

Rationale: Few studies have examined whether changes in participation in civic associations can mitigate depressive symptoms among older disaster survivors. Objectives: 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. Methods: 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. Results: 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. Conclusions: 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.