Trouble déficit de l’attention avec ou sans hyperactivité et troubles du sommeil : de l’enfant à l’âge adulte

Sleep is a frequent complaint among ADHD patients, both children and adults. Numerous studies have highlighted the over-representation of all sleep disorders in this population, with prevalence ranging from 25 to 55%. These sleep complaints include well-defined pathologies such as obstructive sleep apnea syndrome (OSA), restless legs syndrome (RLS) and circadian rhythm disorders. More subjective complaints are also described, such as difficulties in falling asleep, waking up and, above all, staying awake, expressed by excessive daytime sleepiness. RLS is a comorbidity frequently associated with ADHD, in both children and adults, with a prevalence around 3 times higher than in the general population. With regard to OSA, both diurnal and nocturnal expression of this sleep-related respiratory pathology are described. Nocturnal symptoms include snoring, respiratory pauses, night sweats, nocturia… Daytime symptoms include difficulties with attention and concentration, hyperactivity, irritability, impulsivity and difficulty in regulating emotions. As a result, it is not always easy to identify whether the symptoms observed are the expression of OSA alone, or of a comorbid OSA-ADHD situation. Subjects with ADHD more frequently present an evening chronotype and circadian phase delay syndrome than non-ADHD subjects. Several pathophysiological hypotheses have been put forward: genetic, with polymorphisms in the clock genes, or changes in melatonin secretion. Complaints of insomnia are frequently reported by children, parents of ADHD subjects and adults with ADHD. These difficulties exist “throughout the night”, from falling asleep to waking up. Reduced sleep efficiency and diminished sleep quality are also reported. These subjective sleep complaints were, however, poorly confirmed by polysomnographic measurements. Finally, some ADHD subjects exhibit hypersomnolence, described as a “narcolepsy-like” phenotype. Similarly, subjects with narcolepsy have more ADHD symptoms and patients with ADHD have more narcolepsy symptoms, suggesting a continuum between these two disorders. The relationship between sleep disorders and ADHD is diverse and multifactorial. It is not always easy for the clinician to distinguish between sleep debt or poor-quality sleep that can induce ADHD-like symptoms, and the situation of comorbidities between ADHD and various sleep disorders. In the first situation, treatment of the sleep disorder leads to the disappearance of “ADHD-like” symptoms. In the second situation, it is necessary to treat both the ADHD and the sleep disorder, as the two pathologies aggravate each other. This article presents recent data on the main sleep disorders associated with ADHD in children and adults, and proposes practical suggestions to help clinicians in their assessment. Finally, the article proposes a diagram integrating the links between ADHD, ADHD symptoms and sleep disorders.