A Good Night’s Sleep in Children with ASD: What We Know, and What We Still Need To Understand Through Research
Beth A. Malow, MD, MS
Associate Professor of Neurology
Director of the Vanderbilt Sleep Disorders Center
Nashville, Tennessee, USA
Date First Published: April 2, 2007
Date Last Updated: April 2, 2007
Sleep is a basic human need – like food and water. Although we do not yet know precisely WHY we sleep, we do know how we feel when we haven’t had enough sleep – tired, unmotivated, irritable, and just “on edge.” Unfortunately, getting a good night’s sleep can be particularly difficult for children with autism spectrum disorders (ASD), who may resist going to bed, have trouble falling asleep or staying asleep, or wake up too early in the morning. There can be many reasons for these sleep difficulties. Children with ASD may be anxious about falling asleep, may have difficulty settling down for bedtime, may be overly sensitive to sounds in their home, or their “biological clock,” which releases hormones that promote sleep (e.g., melatonin), may not be functioning optimally.
For centuries, sleep was viewed as a time of inactivity; however, we now understand that sleep is an extremely active time, during which hormones are released and memories are solidified. There are two types of sleep: rapid eye movement sleep (REM sleep) and nonrapid eye movement sleep (NREM sleep). Most of our dreaming takes place during REM sleep. The NREM and REM sleep periods cycle throughout the night, and can be measured by performing an electroencephalogram, or EEG study, in which sensors are placed on the scalp and chin and around the eyes. The EEG study is one part of polysomnography, or a sleep study, in which sensors are also used to measure respiration, leg movements, heart rate, and other parameters. Although researchers are still learning the precise functions of REM and NREM sleep, we know that both types of sleep are important for feeling fully alert during the day, and both types of sleep play a role in helping us solidify memories from the day into long term storage. Everyone – children and adults alike – functions better during the day if they get a good night’s sleep. Symptoms such as hyperactivity, inattention, and anxiety can be worsened by not sleeping well, and improved by sleeping better.
Several investigators have examined sleep patterns in children with autism. Most of these studies have used questionnaires completed by parents, which have shown that the predominant concern is that of insomnia—difficulty falling asleep or staying asleep. A few studies have measured sleep using polysomnography or have used actigraphy, which is a wristwatch-like device that monitors rest and movement to estimate when a child is asleep and awake.
Vanderbilt’s Current Sleep Studies in Children with ASD
My team is currently conducting a research program in sleep and ASD at Vanderbilt Kennedy Center for Research on Human Development. Team members include myself, Dr. Beth Malow, Associate Professor of Neurology at Vanderbilt University and Director of the Vanderbilt Sleep Disorders Center, Dr. Wendy Stone, Professor of Psychology and Director of the Vanderbilt Treatment and Research Institute for Autism Spectrum Disorders (TRIAD), and Susan McGrew, Assistant Professor of Pediatrics.
We are performing sleep studies in children with ASD to better understand the relation between sleep, autism, and daytime behavior. We are currently focusing on children ages 4-10 with a clinical diagnosis of ASD, although in the future, we hope to extend our studies to older children with ASD. Through participating in research in the area of sleep and autism, families can help us answer questions such as: (1) Why do some children with ASD not sleep well? (2) How can we help these children sleep better? (3) If these children become better sleepers, will this help their functioning during the day—in school, in therapy classes, at play—as well as assist their parents in helping them overcome their disabilities?
In the December 2006 issue of the journal Sleep (Volume 29, Issue 12, pages 1563-1571), we published a multidimensional approach to characterizing sleep patterns in children with ASD in relation to daytime functioning. Our work included parental surveys of children’s sleep and behavior, the Autism Diagnostic Observation Schedule (ADOS), which is a diagnostic assessment for autism, and overnight sleep studies.
The major findings were:
- Parental concerns about a child’s sleep match up well with the results from sleep studies
- A subset of children with ASD sleep well
- Children with ASD who are “good sleepers” had better social interaction skills on the ADOS and fewer problems with their affect (mood) during the day
These findings suggest that sleep is related to daytime functioning. However, it will be necessary to perform additional research in order to determine whether we can improve daytime functioning through improving sleep. We still do not know the impact of treating sleep disorders in children with autism on their daytime functioning and on that of their families. We also need to do additional work to sort out the most appropriate therapies for helping children with autism sleep better. These questions are the focus of ongoing research being done by our team and others.