The purpose of this study was to determine whether mentally ill chemical abusers (MICA patients) report greater distress than do psychiatric patients who do not abuse psychoactive substances. Thirty-two MICA patients and 31 non-substance-abusing patients completed the SCL-90-R. Group comparisons indicated that MICA patients reported greater levels of somatization, depression, anxiety, obsessive-compulsiveness, paranoia, and psychotic symptoms. MICA patients also reported greater overall distress than did psychiatric patients without substance abuse problems.