Social and economic consequences of alcohol use disorder: a longitudinal cohort and co-relative analysis

BACKGROUND

Although alcohol use disorder (AUD) is associated with future risk for psychosocial dysfunction, the degree to which this arises from a direct causal effect of AUD on functioning v. from correlated risk factors (also known as confounders) is less clearly established.

METHOD

AUD was assessed from Swedish medical, criminal and pharmacy registries. In a large general population cohort, using Cox proportional hazard and regression models, we predicted from the onset of AUD four outcomes: early retirement, unemployment, social assistance, and individual income. We then examined the degree to which these associations were attenuated by relevant confounders as well as by the use of discordant cousin, half-sibling, full-sibling, and monozygotic twin pairs.

RESULTS

In males, AUD most strongly predicted social assistance [hazard ratio (HR) 8.27, 95% confidence interval (CI) 7.96-8.59], followed by early retirement (HR 5.63, 95% CI 5.53-5.72) and unemployment (HR 2.75, 95% CI 2.65-2.85). For income at age 50, AUD was associated with a decrease in income of 0.24 s.d.s (95% CI -0.25 to -0.23). Results were similar in females. Modest to moderate attenuation of these associations was seen in both sexes after the addition of relevant covariates. These associations were reduced but remained robust in discordant co-relative pairs, including monozygotic twins.

CONCLUSIONS

Our results suggest that AUD has a causal impact on a range of measures reflective of psychosocial dysfunction. These findings provide strong support for the drift hypothesis. However, some of the associations between AUD and dysfunction appear to be non-causal and result from shared risk factors, many of which are likely familial.