Predicting relapse with residual symptoms in schizophrenia: A secondary analysis of the PROACTIVE trial.

Introduction: Little attention has been paid to the contribution of individual residual symptom to predict relapse in patients with schizophrenia receiving oral or long-acting injectable (LAI) antipsychotics.

Method: We used the data from the Preventing Relapse on Oral Antipsychotics Compared to Injectables - Evaluating Efficacy (PROACTIVE) study, in which 305 outpatients with schizophrenia were randomly allocated to either biweekly LAI-risperidone (LAI-R) or daily oral second-generation antipsychotics (SGA) and assessed for up to 30 months. Baseline individual symptoms that could predict subsequent relapse were identified, using a Cox proportional hazards model. Moreover, among those who relapsed during the study (n = 73), individual symptoms were compared between baseline and biweekly ratings 8 to 2 weeks before relapse, using the linear mixed model.

Results: A greater score in grandiosity at baseline was significantly associated with subsequent relapse (adjusted HR = 1.24, p = 0.006). When the two treatment groups were separately analyzed, more severe grandiosity (adjusted HR = 1.43, p = 0.003) and less severe hallucinatory behavior (adjusted HR = 0.70, p = 0.013) at baseline were significantly associated with relapse in the oral SGA group, but none was identified in the LAI-R group. Emotional withdrawal was significantly worse 8 and 2 weeks before relapse compared to the baseline (p = 0.032 and p = 0.043, respectively).

Discussion: More severe grandiosity and less hallucination may have led to more frequent relapses in patients with schizophrenia receiving oral antipsychotics, which was not a case in those receiving LAI-R. The exploratory analysis indicates an increase in emotional withdrawal before relapse may be a useful marker for earlier interventions to possibly avert relapse.