Callous-unemotional traits, proactive aggression, and treatment outcomes of aggressive children with attention-deficit/hyperactivity disorder

Abstract

Objective: Stimulant treatment improves impulse control among children with attention-deficit/hyperactivity disorder (ADHD). Decreased aggression often accompanies stimulant pharmacotherapy, suggesting that impulsiveness is integral to aggressive behavior in these children. However, children with high callous-unemotional (CU) traits and proactive aggression may benefit less from ADHD pharmacotherapy, because their aggressive behavior seems more purposeful and deliberate. This study's objective was to determine whether pretreatment CU traits and proactive aggression affect treatment outcomes among aggressive children with ADHD receiving stimulant monotherapy.

Method: We implemented a stimulant optimization protocol with 160 children 6 to 13 years of age (mean [SD] age of 9.31 [2.02] years; 78.75% male) with ADHD, oppositional defiant or conduct disorder, and significant aggressive behavior. Family-focused behavioral intervention was provided concurrently. The primary outcome was the Retrospective Modified Overt Aggression Scale. The Antisocial Process Screening Device and the Aggression Scale, also completed by parents, measured CU traits and proactive aggression, respectively. Analyses examined moderating effects of CU traits and proactive aggression on outcomes.

Results: In all, 82 children (51%) experienced remission of aggressive behavior. Neither CU traits nor proactive aggression predicted remission (CU traits: odds ratio [OR] = 0.94, 95% CI = 0.80-1.11; proactive aggression, OR = 1.05, 95% CI = 0.86-1.29). Children whose overall aggression remitted showed decreases in CU traits (effect size = -0.379, 95% CI = -0.60 to -0.16) and proactive aggression (effect size = -0.463, 95% CI = -0.69 to -0.23).

Conclusions: Findings suggest that pretreatment CU traits and proactive aggression do not forecast worse outcomes for aggressive children with ADHD receiving optimized stimulant pharmacotherapy. With such treatment, CU traits and proactive aggression may decline alongside other behavioral improvements. Clinical trial registration information--Medication Strategies for Treating Aggressive Behavior in Youth With Attention Deficit Hyperactivity Disorder; http://clinicaltrials.gov/; NCT00228046; and Effectiveness of Combined Medication Treatment for Aggression in Children With Attention Deficit With Hyperactivity Disorder (The SPICY Study); http://clinicaltrials.gov/; NCT00794625.

Keywords: CNS stimulants; aggression; attention-deficit/hyperactivity disorder (ADHD); oppositional defiant disorder; psychopathy.

Figure 1

Consolidated Standards of Reporting Trials (CONSORT) Diagram.

Figure 2

Behavioral outcomes for groups with low, middle, and high scores at baseline on proactive aggression and callous-unemotional traits. Note: Each row shows associations between one behavioral outcome and baseline severity groups (low, middle, high) of proactive aggression and callous-nemotional traits. Panels on the left show behavioral outcomes with participants stratified by proactive aggression group. Panels on the right show callous-unemotional traits groups. The table within each chart shows the contrasts between the 3 severity groups (the differences in least-squares means and the 95% CI for that difference) at baseline and at the end of the stimulant monotherapy protocol. APSD C-U = Antisocial Process Screening Device Callous-Unemotional scale; CBCL = Child Behavior Checklist; ConnGI-P = Conners Global Index (Parent Version); R-MOAS = Retrospective-Modified Overt Aggression Scale; VAQ = Vitiello Aggression Scale.

Figure 2

Behavioral outcomes for groups with low, middle, and high scores at baseline on proactive aggression and callous-unemotional traits. Note: Each row shows associations between one behavioral outcome and baseline severity groups (low, middle, high) of proactive aggression and callous-nemotional traits. Panels on the left show behavioral outcomes with participants stratified by proactive aggression group. Panels on the right show callous-unemotional traits groups. The table within each chart shows the contrasts between the 3 severity groups (the differences in least-squares means and the 95% CI for that difference) at baseline and at the end of the stimulant monotherapy protocol. APSD C-U = Antisocial Process Screening Device Callous-Unemotional scale; CBCL = Child Behavior Checklist; ConnGI-P = Conners Global Index (Parent Version); R-MOAS = Retrospective-Modified Overt Aggression Scale; VAQ = Vitiello Aggression Scale.