The relationship between autism spectrum disorder and sleep

DOI: 10.5935/1984-0063.20210050 INTRODUCTION This issue of Sleep Science contains 2 reports related to autism spectrum disorder (ASD), an extremely important and relatively frequent neurodevelopmental disorder. This condition is characterized by impaired reciprocal social interaction and communication, as well as restricted and repetitive patterns of behaviors or interest. It affects 1 in every 40 to 59 children in the United States, with prevalence rates doubling between 2000-2002 and 2010-20121-3. Sleep disturbances are some of the marked challenges faced by young people with ASD, their families and caregivers. Approximately 50% to 80% of children and adolescents with ASD suffer from sleep problems4 in comparison to 20-30% in neurotypical (NT) children4-7. The usual sleep-related complaints and symptoms among ASD children are insomnia, bedtime settling issues, sleep anxiety, night waking, poor sleep quality and sleepdisordered breathing5,8. Problems initiating and maintaining sleep are one the most common concurrent clinical complaints and are less likely to diminish with age compared with NT children9,10. These sleep difficulties commonly faced by children with ASD can produce a significant decrease in the quality of life of all family members as a consequence of sleep deprivation. As sleep is a behavioral and emotional regulator, sleep fragmentation or deprivation can worsen behavioral disturbances in children with ASD11-13, possibly triggering disruptive or inflexible behavior and anxiety14-20. Greater variation in sleep duration and timing have been found to predict subsequent disruptive daytime behavior21. Parents of children with ASD and sleep problems may, thus, have to deal with 2 consequences: firstly, their child ́s behavior problems derived from their sleep issues and secondly, the consequences of their own sleep deprivation. One important question is whether the sleep difficulties of children with ASD also affect their siblings as well as their parents. Understanding the experiences of this population is essential as the relationship that an individual with ASD has with a sibling is typically their longest relationship, and it can have a substantial impact on emotional, behavioral, and psychological outcomes22. However, few studies have examined the sleep of the siblings of children with ASD (ASD-Sib). In this issue of Sleep Science, Naeen et al. provided very interesting data on the sleep of the immediate family of individuals with ASD. The authors investigated 64 children with ASD, 80 of their siblings and 80 NT children using a sleep-wake diary, a school sleep habit questionnaire and a childhood autism spectrum test. Surprisingly, the comparison revealed no significant differences between the children with ASD and their siblings, nor between these 2 groups and the control subjects in terms of their sleep profiles. These results are contrary to those of some previous studies, demonstrating that this is a very complex issue, which probably depends on how siblings deal with the altered family functioning secondary to ASD23. In 2012, Chou et al. reported that ASD-Sib have a higher risk of early insomnia and parasomnias compared to NT children24. Shivers et al. (2019) published a meta-analysis about the degree to which ASD-Sibs function similarly or differently compared to siblings of NT people and to the siblings of individuals with Sandra Doria Xavier*