Risperidone, an
antipsychotic agent with combined
serotonin (5-HT2A) and
dopamine (D2) receptor-blocking properties, is associated with fewer extrapyramidal side effects in adults than conventional
neuroleptics. Approved in 1993 for the treatment of
schizophrenia, recent studies have highlighted its potential in other conditions, such as the management of behavioral disturbances. This phase II, double-blind, placebo-controlled study evaluated the efficacy and tolerability of
risperidone in the treatment of persistent behavioral disturbances in children with borderline intellectual functioning. Thirteen patients (6-14 years) with low IQ (66-85) were enrolled in and completed the 4-week study.
Risperidone, in daily doses of > or = 0.01 mg/kg (mean dose at treatment endpoint = 0.05 mg/kg; mean total dose = 1.2 mg/day), was significantly more effective than placebo in improving Aberrant Behavioral Checklist (ABC)
symptom cluster scores for irritation (p < 0.05) and hyperactivity (p < 0.01), Clinical Global Impression score (p < 0.05), the Visual Analogue Scale score for individual target symptom (p < 0.001), and Personal Assessment Checklist scores for social relationships (p < 0.05) and occupational attitudes (p < 0.05). In addition, the improvement in total ABC score in the
risperidone-treated group was clinically relevant (65% improvement vs. baseline), whereas the placebo-treated patients only improved 7% versus baseline. There was no difference between
risperidone- and placebo-treated groups with respect to the occurrence of extrapyramidal side effects, and
risperidone was well tolerated. In conclusion, short-term
risperidone treatment was well tolerated and significantly more effective than placebo in controlling behavioral disturbances in children with low IQ.