Sleep and Cognition in Individuals with Autism and Down Syndrome

Abstract

Individuals with Autism (ASD) and Down syndrome (DS) have poor sleep (Churchill et al., 2013; Lambert, Tessier, Chevrier, Scherzer, Mottron, and Godbout, 2013; Wiggs and Stores, 2004). However, the type of poor sleep differs between groups. We wanted to explore the nature of parent reported sleep differences in autism and Down syndrome, and compare sleep severity to verbal and nonverbal IQ. We aimed to unveil the relation between sleep and cognition between both groups. Both populations (N=36) were given the Child Sleep Habits Questionnaire (CSHQ), a parent-reported questionnaire, and were tested on IQ by the Kaufman Brief Intelligence Test-II (KBIT-II). Our results yielded significantly higher scores for sleep onset delay and daytime sleepiness in ASD, and a marginally significant increase in bedtime resistance forDS. We compared the 9 subscales of the CSHQ to verbal and nonverbal IQ. Our results showed a significant correlation for ASD between the total sleep disturbance score (TSDS) and verbal IQ. As a more reliable measure of sleep, the CSHQ would be better utilized in conjunction with a more objective measure of sleep, such as polysomnography (PSG).