The comorbidity of alcoholism with anxiety and depressive disorders was examined in four epidemiologic investigations from diverse geographic sites. Despite variability in lifetime prevalence rates for these disorders, there was strong cross-site consistency in the magnitude and specific patterns of comorbidity. Individuals with alcohol abuse or dependence generally experienced a twofold to threefold increased risk of anxiety and depressive disorders. Phobic conditions typically preceded the onset of alcoholism, but no systematic pattern was observed for panic or depressive disorders. Considerable heterogeneity was also observed concerning the impact of comorbid conditions on symptoms of the index disorder. While the presence of comorbid anxiety or depressive disorders was consistently associated with moderate increases in the symptoms of alcohol abuse or dependence, alcoholism was associated with large increases in the number of depressive symptoms and little or no increase in phobic symptoms. The findings are discussed in terms of the self-medication hypothesis and the etiologic heterogeneity of these forms of comorbidity in the general population.