Research Units on Pediatric Psychopharmacology (RUPP) autism network - Background and rationale for an initial controlled study of risperidone

This article reviews the background and rationale for the choice of the aty pical antipsychotic agent risperidone as the first drug to be studied by th e RUPP Autism Network. Risperidone has potent effects on serotonin and dopa mine neuronal systems, which have been implicated in the pathophysiology of autism. Unlike typical antipsychotics, such as haloperidol and pimozide, w hich have been shown to be effective for reducing many of the maladaptive b ehaviors associated with autism, the unique ratio of serotonin to dopamine receptor blockade for risperidone seems to produce a lower risk of acute an d chronic extrapyramidial side effects and enhanced efficacy for the negati ve symptoms of autism. Indirect clinical and preclinical evidence supportin g the use of risperidone to treat impaired social behavior, interfering rep etitive phenomena and aggressions as targets of pharmacotherapy for patient s with autism are reviewed. The safety and tolerability of risperidone also are summarized.