The role of sleep quality and quantity in moderating the effectiveness of medication in the treatment of children with ADHD
Mount Saint Vincent University
There is strong empirical evidence that stimulant medications, such as methylphenidate hydrochloride (MPH), are effective in reducing ADHD symptoms (Ritchers et al., 1995); however, these medications can also cause sleep problems (Corkum et al., 2008). Furthermore, poor sleep has been documented to result in performance deficits in memory, attention and academic performance (Gruber et al., 2011). This study examined: 1) whether stimulant medication is effective in improving performance on measures of memory, attention and academic productivity, and 2) if sleep impacts the relationship between medication and performance. Participants were 21 children (mean age = 9.1 years) with ADHD, who participated in a four week randomized controlled trial of long lasting MPH (2 weeks of medication and 2 weeks of placebo). Participants underwent assessments of sleep (polysomnography and actigraphy) and of cognitive performance. We predicted that there would be a relationship between sleep quantity (duration) and quality (efficiency) medication effects on cognitive performance. Our findings supported stimulant medication as an effective treatment for enhancing alerting attention, executive attention, working memory, and academic productivity performance in children with ADHD. Bivariate correlations between cognitive performance and sleep revealed a significant relationship between sleep duration and executive attention accuracy during incongruent trials of the ANT-I, r= .456, p= .025. A one-way ANOVA was used to compare the good sleep group and poor sleep group (above and below the mean sleep duration, respectively) on executive attention incongruent accuracy. Statistical analysis revealed that children performed significantly different on executive attention incongruent accuracy depending on baseline sleep, F(1, 19)= 6.859, p= .017. Findings are discussed in terms of implications for clinical practice and future research.
Attention deficit hyperactivity disorder , Sleep quality , Cognitive performance