Switching to long-acting injectable risperidone [Risperdal Consta] is associated with further improvement in patients with schizophrenia who are already stable on oral atypical antipsychotic medications, according to three studies presented at the 157th Annual Meeting of the American Psychiatric Association [New York, US; May 2004]. In the first study, involving 119 already-stable patients directly switched to long-acting injectable risperidone for 6 months, the number of patients categorised as 'not ill' or 'very mild' nearly doubled by the end of the study. Furthermore, 31% of patients achieved an improvement in total Positive and Negative Syndrome Scale (PANSS) scores of at least 20% when compared to baseline. In the other two studies, 95 patients who were stable on prior olanzapine or quetiapine therapy were changed to long-acting injectable risperidone for 12 weeks, resulting in further symptomatic improvement for a substantial number of patients. An improvement of at least 20% in PANSS total score was achieved by 44% of patients previously treated with olanzapine and by 35% of patients previously treated with quetiapine.