A trial of quetiapine compared with risperidone in the treatment of first onset psychosis among 15- to 18-year-old adolescents.

The objective of this study was to evaluate the efficacy and tolerability of quetiapine in the treatment of first onset psychosis in older adolescents using risperidone as a comparator. Twenty-two patients with first onset psychosis were randomized to receive quetiapine (up to 800 mg/day) or risperidone (up to 6 mg/day) for 6 weeks. Raters blind to treatment assignment performed outcome symptom ratings. No statistical differences emerged in terms of efficacy or tolerability between the two drugs. However, there were some clinically notable differences that seem to favour the efficacy of risperidone over quetiapine. Patients taking quetiapine, although improved, showed less clinical improvement on scores for total positive and negative symptoms, clinical global severity and depression at 6 weeks than patients taking risperidone. Although both treatments were associated with weight gain and sedation, more patients on quetiapine experienced over 10% weight gain. However, fewer patients who were taking quetiapine required anticholinergic medication or experienced extrapyramidal side effects than patients taking risperidone. Risperidone was significantly more likely to be associated with elevation in serum prolactin levels in this population. In conclusion, the results in this small trial show that adolescent patients may benefit more from treatment with risperidone than quetiapine. However, those susceptible to side effects, particularly hyperprolactinaemia, may be more suitable for treatment with quetiapine.