This retrospective study evaluated relapse in 22 patients with schizop
hrenia, comparing substance abusers with nonabusers. Medication compli
ance was ensured as all subjects were treated with decanoate neurolept
ics. Substance abuse was documented by multiple urine drug screens. Su
bstance abusers had a significantly higher readmission rate to the hos
pital compared to nonabusers. These data suggest that in the presence
of documented medication compliance substance abuse remains a major fa
ctor contributing towards relapse.