Delayed circadian rhythm in adults with attention-deficit/hyperactivity disorder and chronic sleep-onset insomnia

Biol Psychiatry. 2010 Jun 1;67(11):1091-6. doi: 10.1016/j.biopsych.2009.12.032. Epub 2010 Feb 16.


Background: Previous studies suggest circadian rhythm disturbances in children with attention-deficit/hyperactivity disorder (ADHD) and sleep-onset insomnia (SOI). We investigate here sleep and rhythms in activity and melatonin in adults with ADHD.

Methods: Sleep logs and actigraphy data were collected during 1 week in 40 adults with ADHD, of whom 31 reported SOI. Salivary melatonin levels were assessed during 1 night. Sleep measures, circadian activity variables, and dim light melatonin onset were compared between groups of ADHD adults with and without SOI and with matched healthy control subjects.

Results: Compared with control subjects, both groups of ADHD adults had longer sleep-onset latency and lower sleep efficiency. Adults with ADHD and SOI showed a delayed start and end of their sleep period and a delayed melatonin onset compared with adults with ADHD without SOI (p = .006; p = .023; p = .02) and compared with healthy control subjects (p = .014; p = .019; p = .000). Adults with ADHD and SOI also showed an attenuated 24-hour amplitude in their rest-activity pattern, in contrast to those without SOI, who showed a higher day-to-day stability.

Conclusions: These findings demonstrate diurnal rhythm deviations during everyday life in the majority of adults with ADHD that have SOI and suggest that potential benefits of rhythm-improving measures should be evaluated.

MeSH terms

  • Actigraphy
  • Adolescent
  • Adult
  • Attention Deficit Disorder with Hyperactivity / complications
  • Attention Deficit Disorder with Hyperactivity / physiopathology*
  • Chi-Square Distribution
  • Circadian Rhythm / physiology*
  • Humans
  • Melatonin / analysis
  • Middle Aged
  • Saliva / chemistry
  • Sleep / physiology*
  • Sleep Initiation and Maintenance Disorders / complications
  • Sleep Initiation and Maintenance Disorders / physiopathology*
  • Surveys and Questionnaires


  • Melatonin