Depressive Symptoms on the Geriatric Depression Scale and Suicide Deaths in Older Middle-aged Men: A Prospective Cohort Study

OBJECTIVES: Prospective evaluations of the associations between depressive symptoms and suicide deaths have been mainly performed in high-risk populations, such as individuals with psychiatric disorders or histories of self-harm. The purpose of this study was to prospectively examine whether more severe depressive symptoms assessed using the Geriatric Depression Scale (GDS) were associated with a greater risk of death from suicide in a general-risk population. METHODS: A total of 113 478 men from the Korean Veterans Health Study (mean age, 58.9 years) who participated in a postal survey in 2004 were followed up for suicide mortality until 2010. RESULTS: Over 6.4 years of follow-up, 400 men died by suicide (56.7 deaths per 100 000 person-years). More severe depressive symptoms were associated with greater risk of suicide death (p for trend <0.001). The unadjusted hazard ratios (HRs) in comparison to the absence of depression were 2.18 for mild depression, 2.13 for moderate depression, 3.33 for severe depression, and 3.67 for extreme depression. After adjusting for potential confounders, men with a potential depressive disorder had an approximate 90% higher mortality from suicide (adjusted HR, 1.92; 95% confidence interval [CI], 1.38 to 2.68; p<0.001) than men without depression. Each five-point increase in the GDS score was associated with a higher risk of death by suicide (adjusted HR, 1.22; p<0.001). The value of the area under the receiver operating characteristics curve of GDS scores for suicide deaths was 0.61 (95% CI, 0.58 to 0.64). CONCLUSIONS: Depressive symptoms assessed using the GDS were found to be a strong independent predictor of future suicide. However, the estimate of relative risk was weaker than would be expected based on retrospective psychological autopsy studies.