Abuse of and dependence on drugs, alcohol and other substances in schizophrenia are being increasingly recognized and well documented in the literature. It has been suggested that up to 60% of patients with schizophrenia use illicit drugs. A total of 41 subjects who fulfilled DSM-III-R criteria for schizophrenia and substance abuse or dependence were asked to describe their reasons for using such substances, the reasons why they might stop and the subjective effects of the substances. Drugs were reportedly used to increase pleasure, to 'get high' and to reduce depression. However, subjective effects of increased depression and positive symptoms were also reported. These results are considered in the context of potential treatment strategies.