Alcohol consumption and internalising disorders in young adults of ALSPAC: a population-based study

Introduction: Depression and harmful alcohol consumption contribute significantly to the global health burden but in young adults, this relationship is under-researched and conflicted. The aim of this study was to determine the sex-based prevalence and the association between internalising disorders such as depression and alcohol use disorders. Method: Using the Avon Longitudinal Study of Parents and Children, we assessed the sex-specific prevalence of ICD-10 diagnosed GAD, depression and fear-based anxieties (FBA) at 24 years (n=3572). We examined the association between internalising disorders and alcohol consumption using the AUDIT-C 5+ threshold and DSM defined criteria for alcohol dependence. Results: Women reported more GAD (11.6% vs. 6.5%), depression (13.4% vs. 6.9%) and FBA (1.3% vs. 0.5%) than men (p<0.001). Harmful drinking, after adjustment for sex and socioeconomic status, was associated with higher rates of depression (OR 1.8, 95% CI 1.3-2.4, p<0.001), anxiety (OR 1.4, 95% CI 1.0-2.0, p<0.001) and FBA (OR 2.4, 95% CI 1.04-5.56,p=0.009) compared to lower-risk drinkers. In contrast, hazardous drinking was associated with lower rates of GAD (OR 0.69, 95% CI 0.54-0.88) and depression (OR 0.68, 95% CI 0.54-0.86) compared with lower-risk drinkers. Conclusions: Young adults in the UK who drink harmfully are more likely to have depression and other internalising disorders. Further research should test whether there is a J-shaped relationship between alcohol consumption and mental health in young people and whether this varies across the life course.