Risk factors for suicide in depression in Finland: first-hospitalized patients followed up to 24 years.

OBJECTIVE: To examine longitudinally risk factors for suicide in depression, and gender differences in risk factors and suicide methods.

METHOD: We linked data from (i) The Finnish Hospital Discharge Register, (ii) the Census Register of Statistics Finland, and (iii) Statistics Finland's register on causes of deaths. All 56 826 first-hospitalized patients (25 188 men, 31 638 women) in Finland in 1991-2011 with a principal diagnosis of depressive disorder were followed up until death (2587 suicides) or end of the year 2014 (maximum 24 years).

RESULTS: Clinical characteristics (severe depression adjusted hazard ratio [AHR] 1.19 [95% CI 1.08-1.30]; psychotic depression AHR 1.45 [1.30-1.62]; and comorbid alcohol dependence AHR 1.26 [1.13-1.41]), male gender (AHR 2.07 [1.91-2.24]), higher socioeconomic status and living alone at first hospitalization were long-term predictors of suicide deaths. Highest risk was associated with previous suicide attempts (cumulative probability 15.4% [13.7-17.3%] in men, 8.5% [7.3-9.7%] in women). Gender differences in risk factors were modest, but in lethal methods prominent.

CONCLUSION: Sociodemographic and clinical characteristics at first hospitalization predict suicide in the long term. Inpatients with previous suicide attempts constitute a high-risk group. Despite some gender differences in risk factors, those in lethal methods may better explain gender disparity in risk.