Risperidone use in children with Down syndrome, severe intellectual disability, and comorbid autistic spectrum disorders: a naturalistic study.

OBJECTIVE: We report on an open-label, naturalistic study using risperidone to treat disruptive behaviors and self-injury in children with Down syndrome, severe intellectual disability, and comorbid autism spectrum disorders (DS+ASDs). We hypothesized that hyperactivity and disruptive behaviors would improve in response to risperidone treatment consistent with previous studies of children with ASD.

METHODS: Subjects were children (mean age, 7.8 +/- 2.6 years), consisting of 20 males and three females identified through our outpatient Down Syndrome Clinic between 2000 and 2004.

RESULTS: Using the Aberrant Behavior Checklist as the primary outcome measure, all five subscales showed significant improvement following risperidone treatment. The mean duration of treatment was 95.8 +/- 16.8 days, and mean total daily dose was 0.66 +/- 0.28 mg/day. The Hyperactivity, Stereotypy, and Lethargy subscale scores showed the most significant reduction (p < .001), followed by Irritability (p < .02), and Inappropriate Speech (p < .04). Children with disruptive behavior and self-injury showed the greatest improvement. Sleep quality improved for 88% of subjects with preexisting sleep disturbance. Subjects for whom a follow-up weight was available showed a mean weight increase of 2.8 +/- 1.5 kg during the treatment period.

CONCLUSIONS: These findings support our clinical impression of improvement on important target behaviors such as aggression, disruptiveness, self-injury, stereotypy, and social withdrawal. Low-dose risperidone appears to be well tolerated in children with DS+ASD, although concerns about weight gain and metabolic alterations may limit its usefulness over the long term in some children.