Long-term use of risperidone in children with disruptive behavior disorders and subaverage intelligence: efficacy, safety, and tolerability.

Objective: The aim of this study was to assess the long-term efficacy and tolerability of risperidone in the treatment of children and adolescents with disruptive behavior disorder (DBD) and below-average intelligence (IQ < 84) over a cumulative period of 2 years.

Methods: We followed 48 patients (6-15 years of age), who had previously completed a 1- year open-label study of risperidone, for an additional year of treatment. Efficacy was assessed using the conduct problem subscale of the Nisonger Child Behavior Rating Form (N-CBRF) as a primary outcome measure; other N-CBRF subscales, the Aberrant Behavior Checklist (ABC), and the Clinical Global Impression (CGI) of severity were secondary efficacy measures. Safety and tolerability were also assessed.

Results: Of the 48 patients enrolled in this extension study, 33 (69%) completed the trial. The efficacy benefits from the original study were maintained over the course of the extension study. Safety and tolerability were good overall, with the number of adverse events (AEs) decreasing in the extension trial, compared to the original trial. Six patients (13%) discontinued owing to AEs. Weight gain observed in the original trial stabilized during this extension trial. Cognitive testing demonstrated small, but significant, improvements in cognitive ability.

Conclusions: Risperidone is safe and effective in treating DBDs in children over a cumulative period of 2 years.