The prognostic implications of comorbid depression for outcome from alcohol dependence are unclear. It has been suggested that drinking may represent self-medication of depressive disorders and, alternatively, that the pharmacological properties of alcohol induce episodes of depression. In the present study, these questions were investigated by following 84 alcohol-dependent individuals seeking treatment (34% women) for 3 years in a naturalistic, prospective design, During the follow-up period, depressive and drinking outcomes were significantly related. However, there was no evidence that drinking reliably preceded depressive episodes or that depressive episodes precipitated heavy drinking. Despite their high cooccurrence, this study did not find evidence of a strong, direct causal relationship between these phenomena.