Relapse in schizophrenia: is there a relationship to substance abuse?

This retrospective study evaluated relapse in 22 patients with schizophrenia, comparing substance abusers with nonabusers. Medication compliance was ensured as all subjects were treated with decanoate neuroleptics. Substance abuse was documented by multiple urine drug screens. Substance abusers had a significantly higher readmission rate to the hospital compared to nonabusers. These data suggest that in the presence of documented medication compliance substance abuse remains a major factor contributing towards relapse.