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

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.

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.

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.

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.