Objective: Antisocial Personality Disorder (ASPD) and depression frequently co-occur with alcoholism. This study examined the relationship between the presence of ASPD or depression and the course and severity of alcoholism. Method: Alcoholic men (n = 207), recruited from a community- based sample, the Minnesota Twin-Family Study (MTFS), were categorized according to comorbid diagnoses into the following four groups: alcoholics with ASPD (n = 25), alcoholics with depression (n = 24), alcoholics with neither ASPD nor depression, but who were allowed to have additional psychopathology (n = 130) and alcoholics with no other psychiatric diagnoses (n = 28). The four diagnostic subgroups were compared on alcohol and drug use, alcohol-related problems and personality dimensions. Results: ASPD was associated with an earlier age of first intoxication, a more chronic and severe course of alcoholism, more social consequences of drinking and higher levels of drug use. On the whole, depression was associated with a less severe course of alcoholism. Alcoholics with depression and alcoholics with ASPD had nigher negative emotionality, and alcoholics with ASPD had lower constraint scores on the Multidimensional Personality Questionnaire. Conclusions: These findings, derived from a community-based sample, indicate the importance of assessing comorbidity among alcoholics and confirm the association of ASPD with a more severe and chronic course of alcoholism and with higher likelihood of drug abuse.