Sleep problems and circadian rhythm functioning in autistic children, autism with co-occurring attention deficit hyperactivity disorder, and typically developing children: A comparative study.
Autistic kids with ADHD show the most disrupted circadian markers—consider melatonin assessment when sleep issues persist.
01Research in Context
What this study did
Martinez-Cayuelas et al. (2024) compared circadian rhythms in three groups of children. The groups were autistic kids, autistic kids who also have ADHD, and typically developing kids.
Each child wore a small wrist device for one week. The device tracked body movement and skin temperature all night and all day.
What they found
Kids with both autism and ADHD moved the most during the night. Their wrist temperature also rose and fell at unusual times.
Autistic kids without ADHD showed milder changes. The typically developing group had the steadiest sleep patterns.
How this fits with other research
The finding lines up with Lotito et al. (2025). That study also linked worse sleep to lower melatonin levels in autistic children.
It extends the work of Byiers et al. (2025). They showed that autism plus ADHD hurts eye-movement precision. Elena’s team now shows it also hurts circadian timing.
It may seem to clash with Koegel et al. (1992). That older paper found normal cortisol timing in high-functioning autistic kids. The difference is the biomarker: cortisol stayed on schedule, but wrist temperature did not.
Why it matters
If a client has autism and ADHD and still tosses at night, check circadian markers before you blame behavior alone. Ask the doctor about melatonin testing or timed light therapy. A simple wrist temperature log for one week can give you data to guide the plan.
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02At a glance
03Original abstract
Sleep problems are common in autism spectrum disorder (ASD) and different factors can contribute to its occurrence in this population. Misalignment of the biological clock (our circadian system) has been described as one possible explanation. While there is a body of research on sleep problems, relatively less is known about circadian functioning and the specific population of autistic children with co-occurring attention deficit hyperactivity disorder (ADHD). Using an ambulatory circadian monitoring (ACM) system, which resembles a common watch, we gathered sleep parameters and the different rhythms obtained from measuring motor activity, light exposure and distal temperature in 87 autistic children and adolescents, 27 of whom were diagnosed with co-occurring ADHD, and 30 neurotypical children and adolescents as a comparison group. Autistic children and, especially, those with co-occurring ADHD showed greater motor activity during sleep which would be worth studying in future projects which could better define this restless sleep. Of note, we observed an atypical pattern of wrist temperature, with higher values in neurotypical children, followed by autistic children and, ultimately, those with co-occurring ADHD. Temperature is one of the most valuable factors evaluated here as it is closely connected to sleep-wakefulness and the hormone melatonin. Its special pattern during day and nighttime would support the hypothesis of an atypical secretion of melatonin in autistic individuals which would also link with the higher presence of sleep problems in this neurodevelopmental condition.
Autism : the international journal of research and practice, 2024 · doi:10.1177/13623613241254594