Objective: The authors examined the association between alcohol use disorder (AUD) and risk of suicide, before and after accounting for psychiatric comorbidity, and assessed the extent to which the observed association is due to a potentially causal mechanism or genetic and familial environmental confounding factors that increase risk for both.
Methods: Longitudinal population-wide Swedish medical, criminal, and pharmacy registries were used to evaluate the risk of death by suicide as a function of AUD history. Analyses employed prospective cohort and co-relative designs, including data on 2,229,880 native Swedes born between 1950 and 1970 and observed from age 15 until 2012.
Results: The lifetime rate of suicide during the observation period was 3.54% for women and 3.94% for men with AUD, compared with 0.29% and 0.76% of women and men, respectively, without AUD. In adjusted analyses, AUD remained robustly associated with suicide: hazard ratios across observation periods ranged from 2.61 to 128.0 among women and from 2.44 to 28.0 among men. Co-relative analyses indicated that familial confounding accounted for some, but not all, of the observed association. A substantial and potentially causal relationship remained after accounting for a history of other psychiatric diagnoses.
Conclusions: AUD is a potent risk factor for suicide, with a substantial association persisting after accounting for confounding factors. These findings underscore the impact of AUD on suicide risk, even in the context of other mental illness, and implicate the time frame shortly after a medical or criminal AUD registration as critical for efforts to reduce alcohol-related suicide.
Keywords: Alcohol Use Disorder; Co-Relative Design; Comorbidity; Mental Illness; Registry; Suicide.