Importance: Mood disorders and alcohol dependence frequently co-occur. Etiologic theories concerning the comorbidity often focus on drinking to self-medicate or cope with affective symptoms. However, there have been few, if any, prospective studies in population-based samples of alcohol self-medication of mood symptoms with the occurrence of alcohol dependence. Furthermore, it is not known whether these associations are affected by treatment or symptom severity.
Objective: To evaluate the hypothesis that alcohol self-medication of mood symptoms increases the probability of subsequent onset and the persistence or chronicity of alcohol dependence.
Design: Prospective study using face-to-face interviews—the National Epidemiologic Survey on Alcohol and Related Conditions.
Setting: Nationally representative survey of the US population.
Participants: Drinkers at risk for alcohol dependence among the 43 093 adults surveyed in 2001 and 2002 (wave 1); 34 653 of whom were reinterviewed in 2004 and 2005 (wave 2).
Main Outcomes and Measures: Association of alcohol self-medication of mood symptoms with incident and persistent DSM-IV alcohol dependence using logistic regression and the propensity score method of inverse probability of treatment weighting.
Results: The report of alcohol self-medication of mood symptoms was associated with an increased odds of incident alcohol dependence at follow-up (adjusted odds ratio [AOR], 3.10; 95% CI, 1.55-6.19; P = .002) and persistence of dependence (AOR, 3.45; 95% CI, 2.35-5.08; P < .001). The population-attributable fraction was 11.9% (95% CI, 6.7%-16.9%) for incident dependence and 30.6% (95% CI, 24.8%-36.0%) for persistent dependence. Stratified analyses were conducted by age, sex, race/ethnicity, mood symptom severity, and treatment history for mood symptoms.
Conclusions and Relevance: Drinking to alleviate mood symptoms is associated with the development of alcohol dependence and its persistence once dependence develops. These associations occur among individuals with subthreshold mood symptoms, with DSM-IV affective disorders, and for those who have received treatment. Drinking to self-medicate mood symptoms may be a potential target for prevention and early intervention efforts aimed at reducing the occurrence of alcohol dependence.