Remission in schizophrenia: Results from a 1-year study of long-acting risperidone injection

Abstract

Purpose Although treatment advances have improved outcomes in schizophrenia, definitions of remission and recovery are still evolving. Recently proposed criteria for remission (mild or less on multiple core-symptom ratings for at least 6 months) have been applied to a 1-year study of long-acting risperidone injection. Methods In a 50-week, open-label trial, stable patients with schizophrenia or schizoaffective disorder who received long-acting risperidone injection every 2 weeks were assessed using the Positive and Negative Syndrome Scale (PANSS). Remission criteria for the PANSS were applied; global illness severity (Clinical Global Impressions) and patient-rated health status (36-Item Short-form Health Survey) were measured. Results Groups were identified by initial remission status (excluding the time component). Although considered clinically “stable,” 68.2% (394 / 578) did not meet the symptom-severity component of remission criteria at baseline. Following long-acting, injectable risperidone treatment, 20.8% (82) of nonremitted patients achieved symptom remission for at least 6 months, with significant decreases in mean PANSS total and cluster scores ( P < 0.0001) and significantly improved patient-rated health status ( P < 0.0001). Percentages rated as not ill, very mild, or mild increased from 39% to 88%. Among 31.8% (184 / 578) of patients meeting the symptom-severity component of remission criteria at baseline, 84.8% (156) maintained these criteria at endpoint. Conclusions Among previously “stable,” nonremitted patients, many achieved symptom remission after long-acting, injectable risperidone treatment, with significant improvements in multiple symptom domains and patient-rated health status. These results warrant further study as these remission criteria may represent a meaningful clinical endpoint and an important step towards functional recovery.