Establishing Remission and Good Clinical Functioning in Schizophrenia: Predictors of Best Outcome with Long-term Risperidone Long-acting Injectable Treatment

Objective: To measure symptomatic and functional remission in patients treated with risperidone long-acting injectable (RLAI).

Methods: Stable patients with psychotic disorders requiring medication change were switched to open-label RLAI in the switch to risperidone microspheres (StoRMi) trial. In this post-hoc analysis of the trial extension, follow-up was <or=18 months. Symptomatic remission was based on improvement in positive and negative syndrome scale (PANSS) scores and global remission (best outcome) was based on symptomatic remission, functional level, and mental-health quality of life. Predictive factors were evaluated.

Results: Among 529 patients from seven European countries, mean participation duration was 358.7+/-232.4 days, with 18 months completed by 39.9% of patients. Symptomatic remission lasting >or=6 months occurred at some point during treatment in 33% of patients; predictors included comorbid disease, country, baseline symptom severity, baseline functioning, type of antipsychotic before switching, and duration of untreated psychosis. Best outcome occurred in 21% of patients; predictors included baseline symptom severity, baseline functioning, country, schizophrenia type, and early positive treatment course.

Conclusions: One in three patients with stable schizophrenia switching to RLAI experienced symptomatic remission, with combined symptomatic, functional, and quality-of-life remission in one in five patients. Symptomatic remission was predicted by better baseline symptom severity and country of origin, with a significantly greater likelihood of remission occurring among patients in Estonia/Slovenia compared with Portugal. Relapse was predicted by higher mode doses of RLAI, additional use of psychoactive medications, male gender, and country of origin, with relapse occurring most frequently in France and least frequently in Portugal. RLAI dose, additional use of psychoactive medications, and country of origin predicted best outcome, with best outcome occurring most frequently in Estonia/Slovenia and least frequently in Portugal.