What does risperidone add to parent training and stimulant for severe aggression in child attention-deficit/hyperactivity disorder?

Objective: Although combination pharmacotherapy is common in child and adolescent psychiatry, there has been little research evaluating it. The value of adding risperidone to concurrent psychostimulant and parent training (PT) in behavior management for children with severe aggression was tested. Method: One hundred sixty-eight children 6 to 12 years old (mean age 8.89 ± 2.01 years) with severe physical aggression were randomized to a 9-week trial of PT, stimulant (STIM), and placebo (Basic treatment; n = 84) or PT, STIM, and risperidone (Augmented treatment; n = 84). All had diagnoses of attention-deficit/hyperactivity disorder and oppositional-defiant disorder (n = 124) or conduct disorder (n = 44). Children received psychostimulant (usually Osmotic Release Oral System methylphenidate) for 3 weeks, titrated for optimal effect, while parents received PT. If there was room for improvement at the end of week 3, placebo or risperidone was added. Assessments included parent ratings on the Nisonger Child Behavior Rating Form (Disruptive-Total subscale was the primary outcome) and Antisocial Behavior Scale; blinded clinicians rated change on the Clinical Global Impressions scale. Results: Compared with Basic treatment (PT + STIM [44.8 ± 14.6 mg/day] + placebo [1.88 mg/day ± 0.72]), Augmented treatment (PT + STIM [46.1 ± 16.8 mg/day] + risperidone [1.65 mg/day ± 0.75]) showed statistically significant improvement on the Nisonger Child Behavior Rating Form Disruptive-Total subscale (treatment-by-time interaction, p =.0016), the Nisonger Child Behavior Rating Form Social Competence subscale (p =.0049), and Antisocial Behavior Scale Reactive Aggression subscale (p =.01). Clinical Global Impressions scores were substantially improved for the 2 groups but did not discriminate between treatments (Clinical Global Impressions-Improvement score ≤2, 70% for Basic treatment versus 79% for Augmented treatment). Prolactin elevations and gastrointestinal upset occurred more with Augmented treatment; other adverse events differed modestly from Basic treatment; weight gain in the Augmented treatment group was minor. Conclusions: Risperidone provided moderate but variable improvement in aggressive and other seriously disruptive child behaviors when added to PT and optimized stimulant treatment.