Sleep difficulties and sleep disorders are the most common comorbidities reported in individuals with ADHD, affecting approximately 73% of children and adolescents with the condition and up to 80% of adults with ADHD.1,2 The high prevalence of sleep disorders in ADHD patients is a consistent finding, despite differences between studies with regard to population demographics and sleep assessment methodology (eg, subjective or objective measurement; see Table). There have been numerous reports detailing the multidirectional impact of sleep and ADHD on each other, noting that both sleep and ADHD related impairments may originate from common neurobiological pathways.
Assessment of sleep disorders in patients with ADHD requires the clinician to disentangle the relationship between sleep and ADHD in individual patients. For example, a patient with ADHD may have a circadian rhythm sleep disorder that is being driven by difficulty going to bed or as an adverse effect of stimulants. Conversely, problems with attention and disinhibition can be a consequence of poor sleep, such as attention problems secondary to sleep disordered breathing. The relationship between ADHD and sleep can be conceptualized as a bilateral comorbidity in which there is an increase in risk for the comorbid condition when either is present. Furthermore, ADHD and sleep disorders both contribute to the patient’s functional impairment, even though it is the ADHD that is most often the target of clinical attention.
ADHD is inherently a disorder of self-regulation, circadian rhythm, overstimulation, and motor activity, which manifest both by day and by night. Difficulties with sleep and alertness associated with sleep disorders will lead to a pre-narcoleptic state consistent with the presentation of ADHD. Lecendreux and colleagues3 proposed that the agitated sleep, difficulty settling into sleep, and low arousal threshold of children with ADHD could result in hypovigilance that resembles the behavior of an overtired child who “gets a second wind” and becomes hyper or silly. The researchers tested for children with ADHD for sleepiness using the Mean Sleep Latency Test (MSLT) and found significant daytime sleepiness compared with controls. Moreover, daytime sleepiness was directly correlated with parent and teacher ADHD symptom ratings. They suggested that excessive nocturnal motricity might be the expression of a monoaminergic dysfunction.
This theory is relevant to many of the most common sleep disorders associated with ADHD, such as initial insomnia, circadian rhythm sleep disorder, restless legs syndrome, and periodic limb movement disorder. Sleep disordered breathing also makes sense as a risk factor for ADHD, in that hypoxia of any etiology will affect attention, self-control, and executive function. The “paradoxical” improvement in ADHD symptoms with stimulants also makes sense when considered within a theoretical framework that understands the overactivity of ADHD as the consequence of difficulty in regulation of nocturnal, daytime, and circadian rhythm regulation of alertness.
Over the past decade, the complex relationship between ADHD and sleep has become a focus of interest with a marked increase in number of publications. The research has led to a better appreciation of the subjective complaints of patients with ADHD that they “can’t turn their thoughts off.” Four main theories have been suggested as a conceptual model of the relationship between sleep and ADHD.4
First, it may be that sleep problems are a fundamental characteristic of ADHD, as suggested in DSM-III, which considered restless sleep one of the symptoms of ADHD. Second, sleep problems may mimic or cause symptoms that are characteristic of ADHD. Sleep difficulties have an impact on attention, executive functioning, and inhibition consistent with the symptoms of those with ADHD. Thirdly, ADHD and sleep problems may have a reciprocal relationship in that one disorder exacerbates the other in a vicious circle. Both ADHD and sleep problems are also often comorbid for internalizing disorders such as anxiety or depression where sleep difficulty is also part of the presentation. Lastly, it is possible that sleep and ADHD may share common etiological neurobiological pathways.
Dr Weiss is the Director of Child and Adolescent Psychiatry and Ms McBride is Clinical Research Associate, Psychiatric Research Institute, University of Arkansas for Medical Sciences in Little Rock, AR. Dr Weiss has received consulting and honorariums from Purdue Pharma, Rhodes Pharmaceuticals, Shire, and NLS Pharma; she has also received travel reimbursement from Rhodes, Shire, NLS Pharma, The Israeli Society for ADHD, and the World Federation of ADHD. Ms McBride has no conflicts of interest concerning the subject matter of this article.
1. Sung V, Hiscock H, Sciberras E, Efron D. Sleep problems in children with attention-deficit/hyperactivity disorder: prevalence and the effect on the child and family. Arch Pediat Adoles Med. 2008;162:336-342.
2. Wynchank D, Bijlenga D, Beekman AT, et al. Adult attention-deficit/hyperactivity disorder (ADHD) and insomnia: an update of the literature. Curr Psychiatry Rep. 2017;19:98.
3. Lecendreux M, Konofal E, Bouvard M, et al. Sleep and alertness in children with ADHD. J Child Psychol Psychiatry. 2000;41:803-812.
4. Hvolby A. Associations of sleep disturbance with ADHD: implications for treatment. ADHD. 2015;7:1-18.
5. Owens JA, Dalzell V. Use of the “BEARS” sleep screening tool in a pediatric residents’ continuity clinic: a pilot study. Sleep Med. 2005;6:63-69.
6. Corkum P, Tannock R, Moldofsky H. Sleep disturbances in children with attention-deficit/hyperactivity disorder. J Am Acad Child Adolesc Psychiatry. 1998;37:637-646.
7. Markovich AN, Gendron MA, Corkum PV. Validating the Children’s Sleep Habits Questionnaire against polysomnography and actigraphy in school-aged children. Front Psychiatry. 2014;5:188.
8. Chervin RD, Hedger K, Dillon JE, Pituch KJ. Pediatric sleep questionnaire (PSQ): validity and reliability of scales for sleep-disordered breathing, snoring, sleepiness, and behavioral problems. Sleep Med. 2000;1:21-32.
9. Backhaus J, Junghanns K, Broocks A, et al. Test-retest reliability and validity of the Pittsburgh Sleep Quality Index in primary insomnia. J Psychosom Res. 2002;53:737-740.
10. Heaton K, Anderson D. A psychometric analysis of the Epworth Sleepiness Scale. J Nurs Meas. 2007;15:177-188.
11. Corkum P, Lingley-Pottie P, Davidson F, et al. Better Nights/Better Days-Distance Intervention for Insomnia in School-Aged Children With/Without ADHD: a randomized controlled trial. J Pediatr Psychol. 2016;41:701-713.
12. Hartz I, Handal M, Tverdal A, Skurtveit S. Paediatric off-label use of melatonin: a register linkage study between the Norwegian prescription database and patient register. Basic Clin Pharmacol Toxicol. 2015;117:267-273.
13. Lewy A. Melatonin and human chronobiology. Cold Spring Harb Symp Quant Biol. 2007;72:623-636.
14. Van der Heijden KB, Smits MG, Van Someren EJ, et al. Effect of melatonin on sleep, behavior, and cognition in ADHD and chronic sleep-onset insomnia. J Am Acad Child Adolesc Psychiatry. 2007;46:233-241.
15. Weiss MD, Wasdell MB, Bomben MM, et al. Sleep hygiene and melatonin treatment for children and adolescents with ADHD and initial insomnia. J Am Acad Child Adolesc Psychiatry. 2006;45:512-519.