Risperidone for autism spectrum disorder

BACKGROUND: Autistic spectrum disorder encompasses a wide variety of behavioural and communicative problems. Both the core features and non-core features of autism have been targeted in a variety of therapies. Atypical antipsychotic medications, including risperidone, have been used for symptom and behaviour improvement and have shown beneficial outcomes, particularly in certain aspects of the disorder. However, given the nature of the condition presenting in young patients, the risks of these potentially long term therapies must be weighed against the benefits. OBJECTIVES: To determine the efficacy and safety of risperidone for people with autism spectrum disorder. SEARCH STRATEGY: Electronic databases: CENTRAL (Cochrane Central Register of Controlled Trials) 2006 (Issue 3); MEDLINE (1966 to April 2006); EMBASE (1980 to April 2006);PsycINFO (1887 to April 2006); CINAHL (1982 to April 2006); LILACS (1982 to April 2006 ); Clinicaltrials.gov (USA) (accessed April 2006); ZETOC (1993 to April 2006); National Research Register (NRR) (UK) 2006 (Issue 1) were searched. In addition further data were retrieved through contact with pharmaceutical companies and authors of published trials. SELECTION CRITERIA: All randomised controlled trials of risperidone versus placebo for patients with a diagnosis of autism spectrum disorder. All trials had to have at least one standardised outcome measure used for both intervention and control group. DATA COLLECTION AND ANALYSIS: Data were independently evaluated and analysed by the reviewers. Data were evaluated at the end of each randomised controlled trial. Unpublished data were also considered and analysed. MAIN RESULTS: Only three randomised controlled trials were identified. Meta-analysis was possible for three outcomes. Some evidence of the benefits of risperidone in irritability, repetition and social withdrawal were apparent. These must however be considered against the adverse effects, the most prominent being weight gain. AUTHORS' CONCLUSIONS: Risperidone can be beneficial in some features of autism. However there are limited data available from studies with small sample sizes. In addition, there lacks a single standardised outcome measure allowing adequate comparison of studies, and long-term followup is also lacking. Further research is necessary to determine the efficacy pf risperidone in clinical practice.