People with Autism Spectrum Disorder (ASD) often have difficulty sleeping. Studies show that between 50% and 83% of people with ASD experience insomnia (difficulty falling and / or falling asleep) and / or nighttime vigilance during the day, resulting in a disturbance in their circadian rhythms
People with ASD take about 11 minutes longer to fall asleep than neurotypical people. Many wake up several times each night. And the sleep they get is less restful; People with ASD spend only 15% of their sleep hours in REM (Rapid Eye Movement) sleep compared to neurotypical people who spend 23% of their sleep in REM each night. A reduction in REM could further increase the existing learning challenges for people with ASD.2
Without understanding their specific etiology, sleep disorders are often difficult to treat. A better knowledge of the sleep disorders associated with ASD could therefore lead to treatment improvements in these patients.
Possible causes of insomnia with ASD
It is difficult to determine a direct cause of insomnia within the diverse ASD populations. However, there are several neurological factors that appear to be contributing to this.
Sleep-wake cycle
As mentioned earlier, people with ASD often wake up at night or experience drowsiness or wakefulness at inappropriate times. Now researchers believe this could be due to disruptions in their sleep-wake cycle.
This cycle includes the natural changes the body should experience within 24 hours: wakefulness, deep sleep, and REM sleep. Typically, the body alternates between deep and REM sleep every 90 to 120 minutes. In contrast, people with ASD spend less time in REM.
One theory as to why this happens revolves around the two processes that determine waking or sleeping behavior: a homeostatic process that slowly builds drowsiness throughout the day and a circadian rhythm that determines waking hours.
The homeostatic process of promoting drowsiness should increase while awake and produce sleep inducing substances. The circadian process should keep him or her awake for reasonable hours but can easily be influenced by light, hormones, body temperature, genetics, and behavior.
Given the measured reductions in REM sleep in people with ASD, as well as evidence that people with ASD take longer to fall asleep, the researchers suggest that spectrum disorders may affect the synergy of homeostasis and the circadian process
GABA, melatonin and serotonin
Research goes deeper into the world of hormones and neurotransmitters, and suggests that GABA and melatonin may contribute to sleep disorders with ASD. The neurotransmitter GABA activates the GABA-A receptor and regulates the deep sleep REM cycle. However, people with ASD have fewer GABA-A receptors, making it harder to regulate sleep.
This could also explain why some people with ASD have decreased nighttime melatonin levels that coincide with increased serotonin levels: GABA signals affect the final steps in melatonin synthesis. Reduced GABA-A receptors could therefore trigger melatonin deficiency, increased serotonin levels, and difficulty falling or falling asleep
Contributing comorbidities
While these neurological triggers could hinder sleep, it is important to identify and address ASD comorbidities that may contribute to the disorder. Many people with ASD also suffer from gastrointestinal and sensory disorders, both of which could make sleeping difficult. In addition, ADHD and anxiety disorders are common in ASD, which increases sleep disorders, especially when drugs that stimulate ADHD are prescribed to treat ADHD
Identifying the cause for targeted treatments
With so many factors contributing to insomnia, careful monitoring can be key to determining individual triggers. Polysomnography can be an effective method. Performed in a laboratory, this sleep test tracks brain waves, eye and limb movements, and breathing patterns during sleep. It can help identify certain patterns and disorders in deep and REM sleep that may indicate a sleep-wake cycle or obstacles related to neurotransmitters.
Unfortunately, fear of a new environment may throw off many people with ASD. For this reason, some clinicians offer polysomnography at home, albeit with less accurate results. Others recommend actigraphy, in which the person puts on a wristwatch-like device that records their movements throughout the night. While this form of monitoring is less informative, it can detect certain sleeping and waking patterns. Finally, asking for family observation and help with keeping a sleep diary will help you identify specific moments of the disorder
With a better understanding of the causes of disorders, it becomes easier to prescribe drugs to improve sleep. The following are suggested treatment options that have shown promise and target specific causes of insomnia.
1. Melatonin: If decreased melatonin levels affect the sleep of people with ASD, melatonin supplements can help counteract hyperarousal-related sleep disorders. More research is needed to see if melatonin can treat anxiety-related sleep disorders.
2. Antipsychotics: In two studies, one with risperidone and one with quetiapine, participants with ASD showed significant sleep improvements after 6 months and 8 weeks, respectively. In addition, daytime behavior improved with better sleep, but these drugs may have side effects
3. Benzodiazepines and hypnotics: To address issues related to reduced GABA receptors, benzodiazepines (BZDs) can act on GABA-A and G receptors to reduce interference with melatonin production. 4
4th Alpha-2 adrenergic agonists: If comorbid ADHD is causing insomnia, off-label prescriptions of alpha agonists can be helpful. Two open-label studies looked at the use of clonidine for insomnia in children without ASD. The recipe made it easier for participants to fall and fall asleep with few adverse effects. More recently, researchers conducted a guanfacine study in children with ASD. The results showed that 45% of the participants had a reduction in hyperactivity of at least 50%, which could improve sleep. However, in this study, participants experienced side effects such as drowsiness and irritability
Conclusions
Various measures could improve the quality of sleep in children and adults with ASD, and identifying the specific origin of sleep disorders will help them become more successful. Finally, taking comorbidities and other drugs into account – with particular attention to drug interactions – will help reduce sleep disorders while at the same time mitigating undesirable outcomes.
References
1. Ballester P, Richdale AL, Baker EK, Peiro AM. Sleep in Autism: A Biomolecular Approach to Etiology and Treatment. Sleep medicine reviews. 2020; 54: 101357. doi: 10.1016 / j.smrv.2020.101357
2. Neumeyer AM, Anixt J., Chan J. et al. Identification of associations between coexisting diseases in children with autism spectrum disorders. Acad Pediatri. 2019; 19 (3): 300-300; 306. doi: 10.1016 / j.acap.2018.06.014
3. Furfaro H. Sleep Disorders in Autism, explains. Spectrumnews. Published online February 6, 2020.
4. Griffin III CE, Kaye AM, Bueno FR, Kaye AD. Benzodiazepine pharmacology and central nervous system mediated effects. Ochsner J. 2013; 13 (2): 214-2 223
