Parent-reported executive function behaviors and clinician ratings of attention-deficit/hyperactivity disorder symptoms in children treated with lisdexamfetamine dimesylate

Abstract

Objective: The purpose of this article was to describe the relationships between parent-rated executive function (EF) and clinician-rated attention-deficit/hyperactivity disorder (ADHD) symptoms before and after lisdexamfetamine dimesylate (LDX) treatment in children with and without EF deficit.

Methods: In post-hoc analyses of children with ADHD who participated in a 7 week open-label, dose-optimized (LDX 20-70 mg/day) trial, ADHD Rating Scale-IV (ADHD-RS-IV) change scores were compared (using two-sample t tests) between youth with and without clinically significant EF impairment at baseline. Clinically significant impairment was defined as parent-rated Behavior Rating Inventory of EF (BRIEF) Global Executive Composite (GEC) t scores ≥65. Relationships between baseline and endpoint BRIEF and ADHD-RS-IV scores were examined using Pearson correlations and generalized effect linear model. Safety assessment included treatment-emergent adverse events (TEAEs).

Results: At baseline, 265/315 participants (84.1%) had a clinically significant BRIEF score. Their mean (SD) ADHD-RS-IV total score at baseline was 42.1 (6.64) for those with, and 36.5 (6.67) for those without, clinically significant BRIEF. At endpoint, ADHD-RS-IV total and subscale scores were significantly improved (p<0.0001) for both those with and those without clinically significant baseline BRIEF scores. Moderately strong, positive Pearson correlations were observed between BRIEF and ADHD-RS-IV total and subscale scores. In the generalized effect linear model, ADHD-RS-IV change scores were significantly correlated with endpoint BRIEF scores (r(2)=0.35, β=0.73, p<0.0001). In the subgroup without clinically significant BRIEF t scores at endpoint, parents and clinicians rated 90% and 95%, respectively, as improved. In the subgroup with clinically significant BRIEF t scores at endpoint, parents and clinicians rated 69% and 78%, respectively, as improved. TEAEs were experienced by 269/318 (84.9%) participants; most (82.7%) experienced events mild to moderate in intensity. A total of 12/318 (4.1%) participants discontinued because of TEAEs.

Conclusion: Clinically significant impairment of EF behaviors in children with ADHD was associated with more severe ADHD symptoms. LDX therapy improved ADHD symptom severity, and at endpoint, fewer participants displayed impairment of EF behaviors (versus baseline). The parent-rated BRIEF may describe clinically important EF behaviors not assessed by the 18-item ADHD-RS-IV.