Circadian misalignment in patients with autism spectrum disorder (ASD) is associated with sleep architecture with reduced slow-wave sleep and increased REM sleep, according to research presented at the 2022 Annual Meeting of the American Academy of Sleep Medicine and the Sleep Research Society, held from June 4 to 8, 2022, in Charlotte, North Carolina.

Investigators assessed the relationship between sleep architecture and circadian rhythm in patients with ASD using dim light melatonin onset (DLMO) and ambulatory polysomnography.

A total of 11 patients with autism (mean age, 13.07±4.76 years; range, 8 to 23 years; 3 girls) were enrolled. Ambulatory overnight polysomnography was performed in the participants’ homes after a week of systematic desensitization. The participants collected saliva samples on 2 consecutive days. The first evening sample was taken 3 hours before the average sleep onset time, and subsequent samples were taken at 30-minute intervals for a total of 5 evening samples. Melatonin levels were plotted against the time of the saliva samples to calculate DLMO for each day.

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Linear regression was used to establish the best-fit line equation for each plot to measure when melatonin levels initially reached 4 pg/mL and continued to increase.

The percentage of stage N3 sleep during the night had a significantly negative association with the phase angle, which is the time between DLMO and sleep onset. This demonstrated that stage N3 percentage decreases as the phase angle increases.

The phase angle had a significant positive association with REM percentage throughout the night. Also, a significant difference was observed between the mean phase angle for the patients with ASD compared with the mean phase angle expected from a group of age-matched, typically developing individuals.

“Our data revealed that circadian misalignment in individuals with ASD is associated with sleep architecture characterized by reduced slow-wave sleep and increased REM sleep,” stated the researchers. “Given the importance of slow-wave sleep for memory and cognitive functions, this finding may contribute to understanding the relationship between sleep alterations and brain development in ASD.”


Ishii T, Chen J, Parker-Fong K, Kawai M, O’hara R. The circadian misalignment is associated with reduced slow-wave sleep in individuals with autism spectrum disorder. Presented at SLEEP 2022; June 4-8, 2022. Abstract 687.

This article originally appeared on Psychiatry Advisor