LAUSR

Abstract Background While early intervention shows a better outcome in patients with schizophrenia, the benefit of early administration of long-acting injectable antipsychotics (LAI) in schizophrenia is not well-studied. Paliperidone Palmitate is one of the most frequently used LAI, and it is usually administered in the later stage of the illness than oral medication. In this study, the difference in clinical and functional improvement by illness duration after the administration of Paliperidone LAI was evaluated. Methods Patients with schizophrenia who planned to switch their antipsychotic treatment from oral ones to once-monthly Paliperidone LAI were recruited from hospitals in South Korea from 26 July 2010 to 25 July 2017. The clinical and functional change was measured every 4 weeks with Clinical Global Impression Severity (CGI-S) scale and Personal and Social Performance (PSP) scale for 6 months after initiation of Paliperidone LAI. Compared to baseline, improvements after switching to Paliperidone LAI were analyzed based on the duration of illness (DI) (less than 3 years, 3 to 10 years, over 10 years). Results 1166 participants (DI≤3 years, N=240; 310 years, N=484) were enrolled. The change in CGI-S score was significantly different according to the DI and those with DI less than 3 years showed the most improvement in the aspect of clinical symptoms (DI, p<0.001; week, p<0.001; DI*week, p=0.013). All three groups showed significant improvements in PSP scores after the treatment with Paliperidone LAI and patients with DI less than 3 years demonstrated the highest PSP scores (DI, p<0.001; DI*week, p=0.436; week, p<0.001). Discussion Switching to Paliperidone LAI showed significantly better outcomes in schizophrenia patients especially with those with shorter DI. This result suggests that earlier administration of LAI in schizophrenia might lead to better clinical and functional outcomes.