Consistent with our principal hypotheses, individuals who report self-medicating their mood symptoms by drinking alcohol have a greater likelihood of developing alcohol dependence. Once the dependence has developed, self-medicating with alcohol increases the probability of its persistence. In this population-based sample, the odds for developing alcohol dependence were three times greater for those who self-medicated their symptoms relative to those who reported no self-medication. The odds for persistence were also three-fold greater for those who reported drinking to self-medicate their mood symptoms. In our study samples, approximately 12% of new cases of alcohol dependence, and 30% of persistent cases were attributable to alcohol self-medication of mood symptoms. Contrary to our initial hypotheses, the association of alcohol self-medication with incident or persistent dependence did not appreciably vary within strata by sex, age, or race-ethnicity. Furthermore, the associations were elevated among individuals who met full criteria for a mood disorder, as well as among individuals who met some but not all required criteria for an affective condition. This sub-threshold group would be less likely to receive mental health treatment because of the lower severity of their symptoms.
