A 2025 study examined sleep problems, chronotype, and temperament in adolescents with ADHD.
How the Study Was Done
The study included 102 adolescents with ADHD, ages 11–17, recruited from a child and adolescent psychiatry outpatient clinic in Istanbul, and 101 age- and gender-matched controls.
Researchers used diagnostic interviews and standardized questionnaires measuring chronotype, sleep disturbance, and temperament.
What They Found
Adolescents with ADHD reported more sleep disturbance than the comparison group. 63.7% of the ADHD group was classified as evening chronotype, which was more common than in controls.
Within the ADHD group, novelty seeking was higher among adolescents with an evening chronotype and was positively associated with sleep disturbance, including difficulty initiating and maintaining sleep. The ADHD group also scored higher on harm avoidance, while controls scored higher on persistence and self-directedness.
How to Read These Findings
This study identifies associations. It does not show that an evening chronotype causes ADHD, that ADHD causes eveningness, or that every adolescent with ADHD has a delayed body clock.
The participants came from one clinical setting, and the study was cross-sectional. Chronotype, sleep, and temperament were measured at the same period rather than followed over time.
Temperament scores are also not diagnoses. They describe measured traits within this sample.
Practical Clinical Questions
For an adolescent with ADHD and sleep difficulty, it may be useful to ask:
- When do they naturally begin to feel sleepy when school or obligations do not determine bedtime?
- How different are school-day and weekend sleep schedules?
- Is the main difficulty falling asleep, staying asleep, waking, or getting enough sleep?
- Is the sleep schedule mismatched with school timing?
- Are there signs that another sleep disorder needs assessment?
Chronotype is one part of a sleep assessment, not the whole explanation.
Source
Erdem, İ. C., & Bahadır, A. T. (2025). Exploring chronotype, sleep disturbances, and temperament in adolescents with attention deficit hyperactivity disorder. Chronobiology International, 42(7), 879–892. PubMed · DOI