Effectiveness of medication combined with intensive behavioral intervention for reducing aggression in youth with autism spectrum disorder.

Background: The use of antipsychotic medications to treat aggression in youths with autism spectrum disorders (ASD) is based on open-label trials and efficacy studies. There are no studies examining the combined effectiveness of antipsychotic medications and intensive behavioral intervention (IBI) to treat aggression in ASD.

Methods: Youths with ASD and aggressive behavior received IBI. Medication use remained stable during the study period and was coded into antipsychotic, mood-stabilizing, and nonstimulant attention-deficit/hyperactivity disorder (ADHD)/sleep medication classes. Analysis of covariance (ANCOVA) and survival analyses examined the effects of medication classes on the average number of aggressive behaviors and time to behavior plan success.

Results: Thirty-two youths (mean age = 11.16, standard deviation [SD] = 3.31, range = 4-16 years, 75% male) with ASD received aggression reduction plans. Of these, 25 youths were taking at least one psychiatric medication (antipsychotic n = 18, mood stabilizing n = 10, and nonstimulant ADHD/sleep n = 12). Aggression dropped substantially following implementation of IBI (p < 0.001; d = 1.70). Antipsychotic medication use predicted significantly fewer sessions to achieve behavior plan success (chi(2)(1) = 5.67, p = 0.017; d = 0.93). No other medication classes influenced aggressive behavior (largest chi(2)(1) = 0.16, p = 0.694).

Conclusions: Behavioral treatment combined with antipsychotic medication was the most effective approach to reducing aggressive behaviors in youths with ASD. Mood-stabilizing and nonstimulant ADHD/sleep medications did not contribute to aggression reduction.