Meta-analytic study of the benefits and risks of treating chronic schizophrenia with risperidone or conventional neuroleptics.

Data from six randomised, controlled, comparative studies of risperidone and conventional neuroleptics (haloperidol, zuclopenthixol and perphenazine) in the treatment of 911 patients with chronic schizophrenia were analysed to estimate the benefits and risks of treatment. Efficacy and risk of treatment were assessed by means of the Positive and Negative Syndrome Scale (PANSS) and the Extrapyramidal Symptom Rating Scale (ESRS). An effect size (difference between treatments) was calculated from the PANSS and ESRS scores. The effect size of antipsychotic effect favoured risperidone (sizes ranged from 0.22 to 0.37 on the PANSS subscales), and the effect size of safety also favoured risperidone (sizes ranged from 0.18 to 0.36 on the ESRS). An analysis of the proportions of patients requiring antiparkinsonian medication produced an effect size of 0.37 (20% of risperidone patients and 38% of patients receiving a conventional neuroleptic required antiparkinsonian medication). These data indicate that risperidone is a more effective antipsychotic than the conventional agents and causes less severe extrapyramidal symptoms.