Possibilities and limitations in the treatment of aggressive behavior in mentally retarded adults with risperidone

Despite definite indication for psychopharmacologic intervention, severe and persistent symptoms of aggressive and self-injurious behaviour still remain a therapeutic challenge. As recent research has demonstrated, not only the dopaminergic and serotonergic but also the endogenous opiate system plays a role in the pathogenesis of self-injurious behaviour. Nevertheless, the efficacy of classical neuroleptics as well as opiate antagonists is questioned. In open and controlled studies, the administration of the atypical neuroleptic risperidone (a serotonin 2A-dopamine D2 antagonist) was associated with a long-term effect in reducing self-injuries. In our clinical trial, 20 mentally retarded adults presenting with severe self-injurious and aggressive behaviour were administered risperidone over a follow-up period of 35 months. Clinical efficacy was measured with the Disability Assessment Schedule (DAS), conducted in a home for people with mental retardation. In 17 patients, a significant reduction in self-injurious behaviour is shown. Besides, there was a significant overall clinical improvement in behaviour.