The aim of this study was to investigate initial characteristics & improvement after 18 months in patients with comorbidity of severe mental illness & substance abuse. A total of 358 patients were included. 61% of the patients had made suicide attempts. After 18 months, 14 patients had died including 3 suicides. There were significant improvements in all but one Addiction Severity Index area (employment), in psychological symptoms, & in global functioning. No substance abuse was found in half of the patients at follow-up. (35 refs.)