Objective: While rates and correlates of comorbidity have been investigated in the early course of psychosis, little is known about comorbidity in the medium-to-longer term or its relationship with outcome.
Method: A total of 182 first-episode psychosis (FEP) patients who met DSM-IV criteria for a current psychotic disorder 8 years after index presentation were grouped according to concurrent comorbidity [no concurrent axis I disorder; concurrent substance use disorder (SUD); other concurrent axis I disorder; concurrent SUD and other axis I disorder]. Outcomes were compared between groups controlling for relevant covariates.
Results: As much as 39% met criteria for one or more concurrent axis 1 diagnoses. Comorbidity was associated with greater severity of general psychopathology, but not with measures of functioning, treatment or negative symptoms.
Conclusion: Specific combinations of comorbid disorders may influence patterns of psychotic symptomatology. Routine examination of axis I disorders is warranted in the ongoing management of psychosis.