|
 Several sleep problems have been identified as being common among children with attention deficit hyperactivity disorder, including delayed sleep onset, frequent nighttime awakening and feeling tired upon awakening.1-3
In fact, at one time sleep disturbance was listed as one of the diagnostic criteria for ADHD.4 Therefore, it's important for sleep professionals to understand the factors that contribute to poor sleep in this patient population.
Because sleep problems are associated with a variety of psychiatric disorders (e.g., anxiety, depression) it may be that some of the sleep problems experienced by children with ADHD are simply a function of having a psychiatric disorder. It could also be that some aspects of sleep are specific to ADHD. In addition, sleep difficulties may be a consequence of treatment with stimulant medications, such as methylphenidate, that have a frequently reported side effect of insomnia.5
Sleep Survey
The bulk of the research on the association between childhood ADHD and sleep disturbance is derived from parent-report data. A recent parent-report survey revealed that moderate to severe sleep problems occur at least weekly in 19 percent of children with ADHD.6 Parents frequently reported that their children have too much energy to fall asleep or require much less sleep than their same-age peers.
The survey also found that:
61 percent of children with ADHD taking stimulant medication experienced insomnia at least one night per week compared to 32 percent of children with ADHD not taking stimulant medication
frequent nighttime awakening was a weekly problem in 25 percent of children with ADHD on stimulant medication compared to only 9 percent of unmedicated children with ADHD
56 percent of children with ADHD taking stimulant medication were observed to be tired during the day compared to 34 percent of children with ADHD who were not taking stimulant medication.
Thus, sleep disturbances appear to be quite prevalent among children with ADHD, particularly when stimulant medications are being used.5 The findings pertaining to insomnia are particularly striking, as they suggest that using stimulant medications dramatically increases the likelihood that a child with ADHD will have difficulty falling asleep at night.
Objective Measures
The above studies are based solely on parents' subjective impressions of their children's sleep difficulties and may be subject to rater bias. Accordingly, a variety of efforts have been made to obtain more objective measures of children's sleep.
One approach involves having parents keep sleep logs or records of their children's sleep and sleep-related behavior over a specified period of time. For example, Kaplan et al.2 compared sleep logs completed by parents of children with ADHD to those of normal controls. The researchers reported that relative to the control children, children with ADHD were out of bed more frequently once they had fallen asleep, took shorter naps, and experienced more bedwetting and more night sweats. However, sleep logs do not completely eliminate rater bias. In addition, it's often difficult for parents to be aware of and to record all of their children's sleep behaviors.
Activity monitors, small devices worn by the child that record movement, also have been used to obtain objective information about the sleep of children with ADHD. Studies that have incorporated actigraph data have demonstrated that children with ADHD are more active during sleep and during periods of wakefulness.7,8
In addition to sleep logs and actigraphy, polysomnographic studies have been conducted. Recently, a study of 30 boys with untreated ADHD looked at results from multiple sleep latency tests (MSLTs) and computerized reaction time tests following polysomnography. They found significant differences in sleep latencies and reaction times compared to controls, indicating a deficit in alertness in the children with ADHD.9
Other researchers have suggested underlying restless legs syndrome (RLS) with periodic limb movement disorder10 and sleep-disordered breathing, including snoring and sleep apnea,11,12 are important comorbidities associated with ADHD. Further studies using objective sleep measures are warranted in this population.
Pharmacologic Treatment
The medical management of sleep problems in patients with ADHD is directed toward ruling out primary sleep disorders and prudently managing medication. Narcolepsy, sleep apnea and RLS exist in childhood and should be considered in the differential diagnosis. Narcolepsy, in particular, isn't usually diagnosed until late adolescence or early adulthood, yet patients retrospectively have reported that they were symptomatic much earlier and were oftentimes identified as having ADHD.13 Medical therapy for narcolepsy includes stimulants and modafinil, a novel central nervous system stimulant that may work through the orexin/hypocretin system14 that is currently being studied in ADHD patients.15
In terms of sleep apnea, treatment depends on the type and severity of the disorder and may include surgical procedures or nighttime devices such as continuous positive airway pressure.16 RLS, which is also associated with ADHD, is treated with dopaminergic agents or other therapies, including benzodiazepines, gabapentin or iron supplementation.17,18
After a primary sleep disorder is ruled out, adjusting the child's ADHD medication is the best way to manage sleep problems. Prescribed stimulants should be reevaluated, and the dosage should be reduced if possible. Timing of dosages also should be adjusted so that the last dose occurs earlier in the day; an evening stimulant dose rarely allows a child to settle to sleep.
It may be helpful to explore alternatives to stimulants when children experience sleep difficulties. Antidepressants, including the tricyclics and bupropion, may be useful alternatives.19 The alpha-adrenergic agonists, clonidine and guanfacine, also have been widely used to treat the symptoms of ADHD, and these medications tend to augment sleep.20
However, there is ongoing controversy regarding their use in the treatment of ADHD, as it is off-label and not without potential significant toxicity.21 The combination of these agents with stimulants has been an area of particular concern, following reports of four deaths resulting from a combination of clonidine and methylphenidate.22 Review of the actual cases, however, reveals significant preexisting or extenuating factors that do not allow for attributing these outcomes to this combination of medications.23
Conservative dosing with clinical and EKG monitoring, following exclusion of preexisting cardiac disease, and without abrupt discontinuation of clonidine or guanfacine, is probably reasonable and has been widely used clinically.24 Regular use of sedative-hypnotics for the treatment of sleep difficulties in children is rarely used on a long-term basis.
Sleep Hygiene
Modifying children's sleep practices and behaviors can ameliorate many of the sleep problems children with ADHD experience. First, it's very helpful for parents to establish a consistent bedtime routine, which can help children settle down for the night. Suggest that children avoid stimulating activities such as outdoor play just prior to bedtime. Rather, soothing activities, such as coloring and playing board games, work well as part of the evening routine. It's important to adhere to the chosen bedtime, even on weekends. Establish bedtimes and consistent wake times that allow children to obtain adequate amounts of daily sleep. Make sure the evening routine is reasonable from the perspective of both the parent and the child.
In addition to a consistent evening routine and bedtime, parents should establish clear bedtime rules and enforce those rules consistently. For example, a child with ADHD who frequently experiences insomnia should know what exactly she is permitted to do if she is having difficulty falling asleep. Is she permitted to read a book? Can she wake her parents? Is she allowed to play video games? While it is probably not reasonable to expect that a child who can't fall asleep should lie in bed with the lights out for hours on end, there are certain activities that will facilitate sleep and others that will not. A child is unlikely to be able to determine which activities are more likely to promote sleep and instead is likely to opt for the preferred activity unless instructed otherwise.
Several other basic principles of good sleep hygiene are useful to consider. First, eating regular meals and engaging in regular physical activity assist in promoting sleep. In addition, using the bed for sleeping only and not for reading, homework and play is helpful. The bedroom itself should be dark and quiet. Lastly, avoiding caffeinated food and drinks may help to facilitate sleep.
Delayed or disrupted sleep is likely to compromise the daytime functioning of children with ADHD. Thus, sleep problems are likely to exacerbate the attention deficits that these children already experience. Excluding primary sleep disorders, judiciously dosing stimulation or using alternate therapies, and emphasizing good sleep hygiene will help these patients count less sheep.
Dr. Efron is a clinical psychologist at Children's National Medical Center and an assistant professor of psychiatry and behavioral sciences and pediatrics at the George Washington University School of Medicine, Washington, D.C. Dr. Pearl is a pediatric neurologist at Children's National Medical Center and an assistant professor of neurology and pediatrics at the George Washington University School of Medicine. They both staff the Neurobehavioral Sleep Problems Clinic at Children's National Medical Center. For more information, call (571) 226-8393.
|