A-191: Associations Between Daytime Sleepiness and Intraindividual Variability (IIV) in Attention, Speed, and Executive Function in Adults With Attention-Deficit/Hyperactivity Disorder (ADHD)

Abstract

Objective: Recent literature suggests adults with ADHD demonstrate elevated dispersion (metric of across-task intraindividual variability (IIV) in neurocognitive performance). Separately, excessive daytime sleepiness negatively impacts cognition and is prevalent among ADHD populations. However, the relationship between hypersomnolence and elevated IIV in ADHD remains unclear. This study examined whether excessive daytime sleepiness is associated with IIV in attention, speed, and executive function in adults with ADHD. Method/Data Selection: Participants included 396 adults diagnosed with ADHD (Mage=29.91,SD=8.09; Medu=16.14,SD=2.36; 60.4% Female; 37.9% White) following comprehensive neuropsychological evaluation. Study variables included Epworth Sleepiness Scale (ESS) score and tests of attention/speed/executive function (e.g., WAIS-IV Digit Span, Letter-Number Sequencing, Symbol Search, Coding; Trail Making Test; Stroop Color-Word; select Connors Continuous Performance Test (CPT-3) scales). IIV was operationalized as coefficient of variation across tests. ANCOVAs examined ESS-IIV associations. Results/Data Synthesis: Coefficient of variation was computed across standardized T-scores from attention/speed/executive function tests (MCV%=20.9,SDCV%=5.98). An ANCOVA examined whether ESS total score was associated with IIV after controlling for trauma-related symptoms and estimated premorbid intellectual functioning. ESS total score was not significantly associated with IIV in cognitive performance across attention/speed/executive function tests (F(1,365) = .256, p = .613, partial η2 = .001). Conclusions: Excessive daytime sleepiness was not associated with intraindividual variability, as indexed by coefficient of variation, in cognitive performance among adults with ADHD. Findings suggest that subjective hypersomnolence does not appear to contribute to IIV across tasks of attention, speed, and executive function. Other factors (e.g., core ADHD symptoms, sleep quality, emotional functioning) may better account for IIV in this population.