The excess mortality of depression: variation according to cause of death and social factors

Heta Moustgaard, University of Helsinki
Kaisla Joutsenniemi, National Institute for Health and Welfare, Finland
Pekka Martikainen, University of Helsinki

The excess mortality of depression is widely acknowledged but no data on alcohol-related mortality in depression exists. It also remains unclear whether the excess mortality of depression varies according to social factors. This study aimed to quantify the contribution of alcohol-related causes of death in the excess mortality of depression and to assess the modifying effects of social factors on the excess. A register-based 14% sample of community-dwelling Finns aged 40–64 at the end of 1997 was assessed for depression, using register data on antidepressant use and psychiatric hospital care in 1996–1997. The depressed outpatients (n=13,658), depressed inpatients (n=897), and the non-depressed (n=217,140) were followed up for cause-specific mortality in 1998-2007, distinguishing between alcohol- and non-alcohol-related deaths. Depressed out- and inpatients had significant excess mortality for suicide, external and internal causes. Alcohol-related causes accounted for 50% of the excess among depressed men and 30% among women. Excess mortality varied little by social factors, particularly in non-alcohol-related causes. Where variation was significant, the relative excess was larger among those with higher education, home owners, the employed and the partnered. Absolute excess was, however, larger among the less privileged. The results highlight the major role of alcohol in depression mortality.