A group of 30 hospitalized cocaine abusers were studied, along with 124 hospitalized patients who were dependent upon opiates or central nervous system depressants. DSM-III diagnoses, family history data, demographic characteristics, and measures of current depressive symptomatology were compared in the two groups. Nineteen (63%) of the cocaine abusers met criteria for an Axis I diagnosis other than substance abuse; sixteen (53%) had affective disorder. These figures reflected a significantly higher prevalence rate of affective disorder among the cocaine abusers than among the opiate and depressant abusers. In addition, a significantly higher rate of affective disorder was found in the first degree relatives of the cocaine abusers when compared to the other group. Since these findings suggest that a substantial number of cocaine abusers may be suffering from other psychiatric disorders, careful diagnostic evaluation is indicated in this population.