Differences in specific depressive symptoms among community-dwelling middle-aged Japanese adults before and after a universal screening intervention

Purpose This study investigated changes in depressive symptoms after the implementation of a universal screening for depression and subsequent care support. Methods A cluster-randomized study design used 10 subdistricts (2,400 inhabitants aged 40-64 years) in northern Japan randomly assigned in a 2:3 ratio to intervention and control conditions. All 900 residents aged 40-64 in the intervention districts were invited to participate in a 2-year depressive screening program, with a participation rate of 49.2 %. A 4-year ongoing education program occurred in both intervention and control districts. The Center for Epidemiologic Studies Depression Scale (CES-D) was used to assess depressive symptomatology. Repeated cross-sectional samples were surveyed before (n = 1,516, response rate 63.6 %) and after (n = 1,596, 66.4 %) intervention, and the data, clustered according to district, were analyzed at the individual level using a mixed-effects model. Results Significant changes in mean scores between baseline and 5-year follow-up in the intervention group were observed in the Depressive Affect, Somatic Symptoms, and Interpersonal Problems subscales. The difference between the changes over time in the two groups was significant for the three subscales and marginally for the CES-D total scale, but not for the Positive Affect subscale. Conclusions Universal depression screening and subsequent support can be effective in preventing general depressive symptoms, but may not influence psychological well-being, among middle-aged adults in a community setting.