The purpose of this study is to examine the effectiveness of a community-based depression-screening program for suicide prevention among middle-aged adults, the investigators conducted a quasi-experimental intervention study, using a parallel cluster design with communities at municipal level as the unit of allocation and individuals as the unit of analysis.

Suicide is a major cause of premature death, particularly among middle-aged adults, in the majority of Western and Asian countries. A strong association of suicide and depression often indicates the necessity of a high-risk approach for suicide prevention. Improvements in identification and treatment can lead to better depression outcomes and suicide prevention. The investigators hypothesize that a 4-year community-based intervention, consisting of universal depression screening and subsequent care support in the target areas and health education programs, would result in reduced suicide rates among the middle-aged adult population in areas with a high suicide rate.

Inclusion Criteria:

• A municipal area located in the following 4 Aomori Second Medical Zones: Hachinohe, Kamitosan, Aomori, and Tsugaru.
• A municipal area with the higher suicide rate than the prefectural average.
• A municipal area having the sufficient and coverable size to serve the intervention (population 10,000-99,999).

Exclusion Criteria:

• A municipal area receiving further intervention including a depression screening for middle-aged adults.