Differential Effects of Atomoxetine on Executive Functioning and Lexical Decision in Attention-Deficit/Hyperactivity Disorder and Reading Disorder

Abstract

Objective: The effects of a promising pharmacological treatment for attention-deficit=hyperactivity disorder (ADHD), atomoxetine, were studied on executive functions in both ADHD and reading disorder (RD) because earlier research demonstrated an overlap in executive functioning deficits in both disorders. In addition, the effects of atomoxetine were explored on lexical decision. Methods: Sixteen children with ADHD, 20 children with ADHD þ RD, 21 children with RD, and 26 normal controls were enrolled in a randomized placebo-controlled crossover study. Children were measured on visuospatial working memory, inhibition, and lexical decision on the day of randomization and following two 28-day medication periods. Results: Children with ADHD þ RD showed improved visuospatial working memory performance and, to a lesser extent, improved inhibition following atomoxetine treatment compared to placebo. No differential effects of atomoxetine were found for lexical decision in comparison to placebo. In addition, no effects of atomoxetine were demonstrated in the ADHD and RD groups. Conclusion: Atomoxetine improved visuospatial working memory and to a lesser degree inhibition in children with ADHD þ RD, which suggests differential developmental pathways for co-morbid ADHD þ RD as compared to ADHD and RD alone. Clinical Trial Registry: B4Z-MC-LYCK, NCT00191906; http:==clinicaltrials.gov=ct2=show=NCT00191906

Atomoxetine Improved Attention in Children and Adolescents with Attention-Deficit/Hyperactivity Disorder and Dyslexia in a 16 Week, Acute, Randomized, Double-Blind Trial

“…Neither during the acute nor during the open-label treatment phases were significant differences in ADHD symptom improvements noted between atomoxetine-treated subjects with ADHD + D and those with ADHD-only. Our results support the findings of previous, smaller studies that show efficacy of atomoxetine treatment in children with ADHD + D (de Jong et al 2009;Sumner et al 2009). Demonstrating efficacy of atomoxetine in children with a comorbidity of ADHD + D comparable to its efficacy in children with ADHD-only is an important finding for clinicians faced with treatment decisions.…”

“…Enrolled were subjects with ADHD + D (n = 20), dyslexia-only (n = 21), and ADHD-only (n = 16), and healthy controls (n = 26), 9-10 years of age. In this study, treatment with atomoxetine, compared with placebo, improved visuospatial working memory performance and inhibition in subjects with ADHD + D, whereas no effects were seen in the dyslexia-only and ADHD-only groups (de Jong et al 2009). …”

“…Recently, two small clinical trials suggested that atomoxetine is effective in the treatment of ADHD symptoms in children and adolescents with ADHD + D (de Jong et al 2009;Sumner et al 2009). The first study examined the effect, on reading performance and on neurocognitive function, of open-label treatment with atomoxetine in subjects with ADHD + D (n = 36) or ADHD-only (n = 20), 10-16 years of age (Sumner et al 2009).…”

“…Treatment with atomoxetine resulted in reduced ADHD symptoms and improved reading scores in both groups; however, the authors observed different patterns and magnitudes of improvement in the working memory component scores in the different subject groups (Sumner et al 2009). The second study was a randomized, placebo-controlled crossover study (de Jong et al 2009). Enrolled were subjects with ADHD + D (n = 20), dyslexia-only (n = 21), and ADHD-only (n = 16), and healthy controls (n = 26), 9-10 years of age.…”

Enrichment Discrimination Behavior in Spontaneously Hypertensive Rats

“…The results also parallel improvement in visuo-spatial performance in children with ADHD after subchronic atmoxetine [32].…”