Effect of Delayed Clozapine Initiation on Acute Treatment Response in Treatment-Resistant Schizophrenia

Abstract

Objectives: Recent studies have reported that delayed initiation of clozapine can affect clinical response in patients with treatment-resistant schizophrenia (TRS). This study aimed to explore the relationship between delayed initiation of clozapine and acute treatment response.Methods: Sixty-five inpatients with TRS who started clozapine for the first time were included through a retrospective chart review. Acute treatment response was defined as a 30% reduction in the Positive and Negative Syndrome Scale score or a Clinical Global Impression of Improvement score of 1 (very much improved) or 2 (much improved) at 4 weeks after initiating clozapine.Results: After meeting the TRS criteria, the mean delay for initiating clozapine was approximately 13.8 months. The delay was shorter in patients who showed a better response to clozapine in logistic regression analysis (p=0.037).Conclusion: Our findings suggest that reducing the delay in initiating clozapine increases the effectiveness of clozapine in patients with TRS.