Alcohol-related deaths and social factors in depression mortality: a register-based follow-up of depressed in-patients and antidepressant users in Finland

BackgroundExcess mortality of depression is established for various causes of death, but evidence is scarce on alcohol-related causes. It also remains unclear whether the magnitude of the excess varies by social factors. This study aimed to quantify the contribution of alcohol-related causes of death and to assess modifying effects of socioeconomic position, employment status, and living arrangements in the excess mortality of depression.MethodsA 14% sample of community-dwelling Finns aged 40-64 at the end of 1997 was assessed for depression, using register data on psychiatric hospital care and antidepressant use in 1996-1997. Depressed in-patients (n=897), out-patients using antidepressants (n=13,658), and non-depressed individuals (n=217,140) were followed up for cause-specific mortality in 1998-2007, distinguishing between alcohol- and non-alcohol-related deaths, and testing for variation in the excess mortality according to baseline social factors.ResultsDepressed in- and out-patients had significant excess mortality for suicide (age-adjusted rate ratios RR=3.77 for men and RR=6.35 for women), all accidental and violent causes (RR=3.47 and RR=4.43), and diseases (RR=1.67 and RR=1.41). Of the excess, alcohol-related causes accounted for 50% 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 socioeconomic position and the employed. Absolute excess was, however, larger among those with lower socioeconomic position, the unemployed, and the unpartnered.LimitationsDepression was measured indirectly by hospital and antidepressant use.ConclusionsThe results highlight the major role of alcohol in depression mortality.