The causal interplay between depression and alcohol use from adolescence to young adulthood

Depression is often comorbid with alcohol use problems, and sex differences may further complicate this interplay.
A research team conducted a longitudinal study using a large European adolescent cohort assessed at ages 14, 16, 19, and 23. Depression and alcohol use were measured using standardised behavioural scales. Cross-lagged analysis, improved Mendelian randomization (MR) analysis, and mediation analysis were conducted to infer the causal interplay.
A total of 2,110 teenagers took part in the study at the beginning. At first, depression and alcohol use were positively related, meaning that teens with more depression tended to drink more alcohol. However, this link became weaker over time and eventually turned negative. Depression and alcohol-related problems stayed strongly connected across all three follow up time points in the study (ages 16, 19 and 23). Further analysis showed that depression could predict later alcohol problems.
Additional genetic analyses supported a two-way relationship between depression and alcohol use. Interestingly, MR results also suggested that moderate alcohol consumption might slightly reduce depression. This effect was especially seen in females at the third follow-up (age 23) and was largely explained by anxiety levels and the personality trait neuroticism. These findings were confirmed in an independent matched sample of 562 participants from the Human Connectome Project.
Depression may predict future alcohol use problems, whereas moderate alcohol consumption might alleviate depressive symptoms, especially in females.
Source: Wang, X., Xiang, S., Kang, J., et al. The causal interplay between depression and alcohol use from adolescence to young adulthood: a Mendelian randomization study. Psychological Medicine. 2026;56:e28.