Risperidone: new indication. Behavioural disorders in children with autism or mental disabilities: no progress

(1) Sedative drugs are one option when autistic or mentally disabled children have behavioural disorders that place them (or other people) in physical danger. Among the classic neuroleptics, haloperidol is the drug with the best-documented efficacy and safety. Placebo-controlled trials have also shown lithium to be effective for this use. (2) Clinical evaluation of risperidone in children with mental disabilities includes 3 placebo-controlled double-blind trials, 2 of which involved 118 and 110 children aged from 5 to 12 years who were treated for 6 weeks. All 3 trials showed a partial behavioural improvement in about 75% of children receiving risperidone, versus about 30% of children in the placebo groups. (3) Clinical evaluation of risperidone in autistic children includes 2 placebo-controlled double-blind trials involving 110 and 79 children who were treated for 8 weeks. One of these studies has been published in detail: 69% of children partially improved with risperidone, versus 12% of the children on placebo. (4) Given the absence of clinical trials comparing risperidone with haloperidol or lithium, there is no evidence that risperidone is more effective than these other treatments. (5) The principal adverse events observed in short-term trials of risperidone were drowsiness (affecting about 50% of children), weight gain (about 1.2 kg per month during the first months of treatment), and hyperprolactinaemia (affecting about 12% of children). Extrapyramidal disorders were infrequent during short-term trials, but their incidence reached about 25% after a year of risperidone treatment. (6) The impact of long-term risperidone therapy on growth and mental development is not known. (7) In France treatment is about 7 times more expensive with risperidone than with haloperidol. (8) In practice, the risk-benefit balance of risperidone in the treatment of autistic or mentally disabled children with behavioural disorders is no better overall than that of older products such as haloperidol and lithium, which, in the absence of anything better, remain the standard drugs.