Sleep microstructure in attention deficit hyperactivity disorder according to the underlying sleep phenotypes

Area of Science:

• Neuroscience
• Pediatrics
• Sleep Medicine

Background:

• Attention deficit hyperactivity disorder (ADHD) is linked to altered sleep microstructure, specifically reduced EEG slow component during NREM sleep.
• Previous research often overlooked or excluded sleep disorders in ADHD studies, despite their known impact on sleep architecture.

Purpose of the Study:

• To investigate the cyclic alternating pattern (CAP) in a clinical sample of drug-naïve children with ADHD, considering potential sleep disorders.
• To differentiate ADHD subtypes based on sleep microstructure, particularly distinguishing primary ADHD from forms associated with sleep apnea or epileptic activity.

Main Methods:

• Conducted attended video-polysomnography on 27 drug-naïve children with ADHD and 23 controls (mean age ~10.4 years).
• Performed blinded visual analysis of the cyclic alternating pattern (CAP) during sleep.
• Objectively characterized sleep disorders in the ADHD cohort, including narcolepsy-like phenotype, insomnia, arousal, movement disorders, obstructive sleep apnea, and sleep-related epileptiform discharges.

Main Results:

• Children with ADHD exhibited a similar overall CAP rate (~50%) to controls.
• A significantly higher CAP rate during N3 sleep was observed in ADHD children with obstructive sleep apnea.
• ADHD children without epileptic abnormalities or obstructive sleep apnea showed a trend towards lower CAP rate and A1 index.

Conclusions:

• The study highlights the high prevalence of sleep disorders in children with ADHD.
• Sleep microstructure, specifically CAP rate, may help differentiate primary ADHD from ADHD associated with obstructive sleep apnea or epileptic activity.
• Further research is warranted to explore the clinical implications of these findings for ADHD diagnosis and treatment.