Clozapine-Associated Neutropenia among People on Clozapine in Japan: A Nationally Representative Retrospective Cohort Study
Abstract
BACKGROUND AND HYPOTHESIS: Clozapine is the most effective antipsychotic for treatment-resistant schizophrenia, but use is constrained by potentially life-threatening neutropenia and mandatory hematological monitoring. Evidence from Western cohorts suggests risk is concentrated early in treatment, yet data from Japan where monitoring is stringent, remain limited. STUDY DESIGN: Retrospective study including all patients prescribed clozapine from July 2009-January 2020 in Japan. Mild neutropenia was defined as absolute neutrophil count (ANC) 1.0-1.5 × 109/L, and serious neutropenia as ANC
Fields of Study & Subjects
Schizophrenia research and treatment
Blood disorders and treatments
Tryptophan and brain disorders
Publication details
- Journal / source
- Schizophrenia Bulletin
- Publisher
- Oxford University Press (OUP)
- Volume
- 52
- Issue
- 3
- Publication date
- 10 April 2026
- Language
- EN