The Contributions of Cognitive Abilities to the Relationship between ADHD Symptoms and Academic Achievement.

The main objective of this study was to examine whether increased levels of inattentive (INA) and hyperactive/impulsive (H/I) behaviours were associated with lower scores on standardized tests of achievement in basic reading, spelling, and math skills, after accounting for certain known background risk factors and cognitive processes. Clinical assessment data from a rigorously diagnosed, stimulant-medication-naïve sample of 354 elementary school-aged children experiencing academic difficulties and behavioural symptoms of inattention and/or hyperactivity/impulsivity were analyzed. Although higher scores of INA were significantly associated with lower scores in reading, spelling, and math, these associations did not persist when cognitive variables were added to the models. H/I was associated with math achievement, along with cognitive and background variables. Overall, cognitive variables accounted for the majority of the variance across basic reading, spelling, and math skills. Additionally, the only background demographic variables associated with academic achievement were age and sex for spelling and math. This finding highlights the importance of looking beyond observable INA and H/I behaviours to determine the underlying factors influencing academic achievement. Accurate identification of deficits in specific academic skills and the underlying factors influencing achievement in these skills are essential components in determining appropriate recommendations and targeted interventions.

Sleep and Attention in Children With ADHD and Typically Developing Peers.

OBJECTIVE: The objective of this study was to examine the relationships between sleep and attention in both typically developing (TD) children and children with ADHD. METHOD: The current study examined sleep and attention in 50 children, from 6 to 12 years of age (25 ADHD, 25 TD). Attention was measured using the Conners' Parent Rating Scale-Revised: Long Version and the Attention Network Test-Interaction (ANT-I), which provided an objective measure of alerting, orienting, and executive attention. Sleep was objectively measured using actigraphy. RESULTS: Children with ADHD had poorer alerting and executive attention on the ANT-I, as well as poorer parent-reported attention. In addition, poor sleep predicted performance on alerting attention for children with ADHD and TD children, whereas the interaction between poor sleep and ADHD diagnosis predicted executive attention scores. CONCLUSION: The findings of the current study highlight the importance of ensuring children are getting good quality sleep to optimize attention, particularly for children with ADHD.

Concordance of actigraphy with polysomnography in children with and without attention-deficit/hyperactivity disorder.

This study sought to: (1) compare actigraphy-derived estimated sleep variables to the same variables based on the gold-standard of sleep assessment, polysomnography; (2) examine whether the correlations between the measures differ between children with attention-deficit/hyperactivity disorder and typically developing children; and (3) determine whether these correlations are altered when children with attention-deficit/hyperactivity disorder are treated with medication. Participants (24 attention-deficit/hyperactivity disorder; 24 typically developing), aged 6-12 years, completed a 1-week baseline assessment of typical sleep and daytime functioning. Following the baseline week, participants in the attention-deficit/hyperactivity disorder group completed a 4-week blinded randomized control trial of methylphenidate hydrochloride, including a 2-week placebo and 2-week methylphenidate hydrochloride treatment period. At the end of each observation (typically developing: baseline; attention-deficit/hyperactivity disorder: baseline, placebo and methylphenidate hydrochloride treatment), all participants were invited to a sleep research laboratory, where overnight polysomnography and actigraphy were recorded concurrently. Findings from intra-class correlations and Bland-Altman plots were consistent. Actigraphy was found to provide good estimates (e.g. intra-class correlations >0.61) of polysomnography results for sleep duration for all groups and conditions, as well as for sleep-onset latency and sleep efficiency for the typically developing group and attention-deficit/hyperactivity disorder group while on medication, but not for the attention-deficit/hyperactivity disorder group during baseline or placebo. Based on the Bland-Altman plots, actigraphy tended to underestimate for sleep duration (8.6-18.5 min), sleep efficiency (5.6-9.3%) and sleep-onset latency, except for attention-deficit/hyperactivity disorder during placebo in which actigraphy overestimated (-2.1 to 6.3 min). The results of the current study highlight the importance of utilizing a multimodal approach to sleep assessment in children with attention-deficit/hyperactivity disorder.