Pre-pandemic individual- and community-level social capital and depressive symptoms during COVID-19: A longitudinal study of Japanese older adults in 2019-21.

During a pandemic, it is important to know whether social capital can mitigate the risk of mental disorders, given the restrictions on social interactions. However, evidence using longitudinal data is scarce. This study examined the association between pre-pandemic social capital and depressive symptoms during COVID-19 among older adults. We used longitudinal data from the Japan Gerontological Evaluation Study (JAGES), including 8291 participants aged 65 or older who were physically and cognitively independent and not depressed at baseline. We conducted baseline and follow-up mail surveys in ten municipalities in Japan from November 2019 to January 2020 (pre-pandemic period) and from November 2020 to February 2021 (pandemic period), respectively. We measured depressive symptoms using the 15-item Geriatric Depression Scale. Social capital was measured with three validated subscales, namely, civic participation, social cohesion, and reciprocity. We performed a multilevel logistic regression analysis to examine the association. A total of 1089 (13.1%) participants newly developed depressive symptoms during the pandemic. The logistic regression showed that pre-pandemic individual-level social cohesion (odds ratio = 0.79, 95% confidence interval: 0.73 to 0.86) and reciprocity (0.89, 0.82 to 0.96) and community-level reciprocity (0.93, 0.88 to 0.98) were negatively associated with the odds of depressive symptoms. Even after adjusting for declines in social capital during the pandemic, the observed associations of pre-pandemic social capital remained. Fostering social cohesion and reciprocity may increase resilience to mental disorders during a pandemic of infectious disease.