International trends in clozapine utilisation prevalence in adults, adolescents and older people: An observational study in 42 countries between 2015 and 2024

The study analyzed clozapine use, the only evidence-based treatment for treatment-resistant schizophrenia, across 42 countries between 2015 and 2024 in a population of over 1.1 billion people. In 2024, clozapine prevalence in adults was highest in Croatia (415.3 per 100,000 population) and Finland (302.0 per 100,000), and lowest in Oman (0.5 per 100,000) and Ethiopia (0.3 per 100,000), representing a 1,384-fold difference. Overall, clozapine use in adults increased by 17 percent over the decade, from 44.7 to 52.2 per 100,000 population. Use was most common in individuals aged 50 to 59 years and varied significantly between countries. The study found that international differences in clozapine utilization were not explained by socioeconomic factors or healthcare system characteristics, suggesting an important role for clinical and service-level barriers.