by Leslie E. Packer, PhD
Last updated March 5, 2015
How common are sleep problems in the general population? Owens et al. (2000) reported that 37% of school children they tested (from grades K – 4) suffered from at least one sleep-related problem. For adolescents, Roane and Taylor (2008) found that 9.4% reported symptoms of insomnia.
Not surprisingly, sleep disorders contribute significantly to academic, motoric, behavioral, and social-emotional difficulties, but Restless Legs Syndrome, Periodic Limb Movements of Sleep, narcolepsy, insomnia, and sleep apnea do not all have the same effect on daytime functioning.
Because children and teenagers with the kinds of neurobehavioral disorders described on this web site are likely to have sleep-related problems, this article will provide a brief overview of some different types of sleep disorders and what we know about the kinds of sleep problems associated with different disorders.
TYPES OF SLEEP DISORDERS
Out of all the sleep disorders, the one most familiar to the public is insomnia. Insomnia is a sleep disorder characterized by difficulty falling asleep, difficulty staying asleep, and/or poor quality sleep. Insomnia can lead to difficulties in daytime functioning and psychological distress. Although estimates of how common insomnia is have varied across studies, insomnia appears to occur in about 10% of the population, and is more common in women and the elderly.
Restless Legs Syndrome
Restless legs syndrome (RLS) is a neurological disorder characterized by sensations of discomfort in the legs during periods of inactivity. People with RLS report sensations of crawling, creeping, and/or pulling or tingling. The sensation causes an irresistible urge to move the legs, and the discomfort is generally relieved by moving or stimulating the legs. RLS symptoms usually occur before sleep onset and make it difficult for the individual to fall asleep.
Periodic Limb Movements of Sleep
Periodic limb movements of sleep (PLMS) involves episodes of repetitive, stereotyped limb movements during sleep; these movements are usually leg movements and associated with increased awakenings during the night. The individual may not be aware of these movements and/or of the awakenings.
RELATIONSHIP BETWEEN OTHER DISORDERS AND SLEEP PROBLEMS
Many of the conditions described on this web site are associated with sleep disturbances. In some cases, such as mood disorders, sleep disorders are even part of the diagnostic criteria. The following is just a brief overview of some of the research on various disorders and sleep problems:
ADHD and Sleep Problems
Sung, Hiscock, et al. (2008) investigated the prevalence of sleep problems in 239 children with ADHD and attempted to correlate sleep meausres with quality of life (QOL), daily functioning, and school attendance; caregiver mental health and work attendance; and family functioning. The study did not use objective measures of sleep problems, and used caregiver reports as their mesaures of severity of sleep problems, if any. The investigators found that sleep problems were common: only 26.7% of caregivers reported that the child had no sleep problems, while 28.5% reported mild problems and 44.8% reported moderate or severe sleep problems. Moderate or severe sleep problems were associated with poorer child psychosocial QOL, child daily functioning, and caregiver mental health (yes, if our kids have moderate or severe sleep problems, it can stress us out: children with sleep problems are more likely to be late to school, and parents are more likely to be late to work). But what kind of sleep problems do children and adults with ADHD have?
In 1999, Picchietti et al. reported that unmedicated children who were newly diagnosed with ADHD had significantly more periodic limb movements in sleep (PLMS), and that they had significantly more arousals (awakenings) and overall less sleep than their non-ADHD peers. Similarly, Owens et al. reported that children with ADHD had more difficulty falling asleep and staying asleep than their non-ADHD peers. They recommended that all children with ADHD be screened for sleep disturbances, particularly sleep-disordered breathing.
Subsequent research by others found that 44% of clinical samples of patients with ADHD have Restless Legs Syndrome (Cortese et al., 2005) and that adults with ADHD have more nocturnal activity, reduced sleep efficiency, more nocturnal awakenings, and reduced percentage of REM sleep (Sobanski et al., 2008). Of note, Shochat et al. (2009) found a correlation between parental reports of sleep problems and behavior in children with ADHD, but the relationship was not as strong as we might have expected once they took sensory defensiveness into account. Tactile sensitivity was a significant predictor for sleep, while sensation seeking and tactile sensitivity were significant predictors for behavior.
Could treating PLMS impact the symptoms of ADHD or school functioning? In an intriguing pilot study by Walters et al. (2000), 7 children with ADHD and PLMS or ADHD and Restless Leg Syndrome (RLS) were given monotherapy with either levadopa or pergolide* (both medications affect dopamine levels in the brain). The investigators reported that after treatment, three children no longer met the criteria for ADHD and three reverted to normal on the Test of Variable Attention. ADHD symptoms improved in all seven children (as measured by both the Connors and the Child Behavior Checklist). A significant improvement also occurred in the visual, but not verbal, memory scores on the Wide Range Assessment of Memory and Learning. Five of the seven children continued on dopaminergic therapy for at least 3 years after treatment initiation with good response.
Unfortunately, stimulant medications typically used to treat ADHD may impair sleep, and those medications do list insomnia as a possible side effect. Research by Corkum et al. (2008) confirmed that although methylphenidate was effective in treating the symptoms of ADHD in children, it resulted in significantly less total sleep time and significantly longer latency to sleep. In adults with ADHD, however, methylphenidate appeared to improve sleep. Sobanski et al. (2008) found that methylphenidate improved sleep efficiency as well as subjective feelings of improved restorative value of sleep.
More recently, Harriet Hiscock and her colleagues (2015) conducted research on sleep hygiene interventions and their impact on functioning in 244 children with ADHD who were seen in pediatric practices in Australia. Intervention families reported a greater decrease in ADHD symptoms and greater improvements in all other child and family outcomes except parental mental health. Teachers reported improved behavior of the children at three and six month follow-ups.
Mood Disorders and Sleep Impairment
Depressed patients commonly complain of difficulties initiating sleep, maintaining sleep, and awakening early in the morning. Some studies indicate that lack of sleep is associated with increased risk of suicidal ideation and increased risk of suicide attempts in the general population, independent of the impact of any comorbid disorders. For depressed patients, then, sleep problems can really exacerbate their problems. As Walsh (2004) summarizes: although insomnia is often perceived as a symptom of depression, it is also both a precursor of depression and is associated with a substantial increase in the relative risk of major depression.
Bipolar Disorder also has a significant association with sleep problems. Hypomania or mania can actually be induced in a significant subset of bipolar patients by using sleep deprivation. A number of studies have demonstrated that sleep disturbance is the most common precursor of mania.
But what happens to bipolar children and adults when they are in a normal (euthymic) mood state? Do they still have sleep disturbances? Harvey et al. (2005) compared euthymic bipolar patients to non-bipolar patients with insomnia, and subjects with good sleep. A combination of self-report and objective measures were used. They found that 70% of the euthymic bipolar patients (still) had a clinically significant sleep disturbance characterized by impaired sleep efficiency, higher levels of anxiety and fear about poor sleep, lower daytime activity levels, and a tendency to misperceive sleep.
Staton (2008) provides a review of sleep problems in childhood-onset Bipolar Disorder in terms of subtypes of bipolar patterns as they relate to sleep onset and need for sleep. Whereas children and adolescents with part-day manic cycles and chronic mixed conditions typically exhibited delayed sleep onset, but not a decreased need for sleep, children with days-long manic cycles or chronic mania typically reported decreased need for sleep.
On a hopeful note, a recent pilot study by Soehner et al. (2015) suggests that treating the insomnia can improve mood state, sleep, and functioning for patients with Bipolar Disorder. Comparing a cognitive-behavior therapy (CBT) for insomnia to psychoeducation (PE) as a control, the investigators reported that at 6-month follow-up, the CBT group had fewer days in a bipolar episode relative to the PE group (3.3 days vs. 25.5 days), a lower hypomania/mania relapse rate (4.6% vs. 31.6%), and a marginally lower overall mood episode relapse rate (13.6% vs. 42.1%).
Tourette’s Syndrome and Sleep Problems
Children and adolescents with Tourette’s Syndrome (TS) report significantly more sleep problems than their non-TS peers. For children or teenagers with Tourette’s, sleep onset may be delayed because they first have to “get their tics out.” They lie down to go to bed and may tic explosively or vigorously for an hour or more. But other sleep problems also interfere with getting a good night’s sleep.
Kostanecka-Endress et al. (2003) obtained objective measures of sleep on 17 unmedicated children and teens with TS who did not have comorbid ADHD and a control group. They found that children with TS demonstrated longer sleep period time, longer sleep latency, reduced sleep efficiency, and prolonged wakefulness after sleep onset. Their sleep profiles showed significantly more time awake and less sleep stage II. However, REM sleep variables, slow-wave sleep, and number of sleep stage changes were unaffected.
A study by Ghosh et al. (2014) assessed sleep problems in 123 patients with Tourette syndrome, 75 (61%) of whom had comorbid ADHD. The sleep problems observed included problems in the nature of sleep, abnormal behaviors during sleep, and impact of sleep disturbances on quality of life. They reported that 31 (65%) of the 48 Tourette-only patients and 48 (64%) of the 75 Tourette + ADHD patients met criteria for some type of sleep disorder, confirming that sleep problems are part of TS itself and not just mediated by ADHD.
Obsessive-Compulsive Disorder and Sleep Problems
Children and teenagers with anxiety disorders or Obsessive-Compulsive Disorder also experience sleep problems, but of a different kind. Students with OCD may stay up late into the night working to get a paper “perfect,” or may be so anxious about a school assignment that they can’t get a good night’s sleep. Other children and adolescents with OCD may have time-consuming rituals that they must engage in at night that prevent them from getting to sleep at a reasonable hour: toys must be lined up “just so,” there may be extensive and time-consuming hygiene rituals instead of just being able to take a quick shower and get to bed, the bedding must be in a particular way, or they may have extensive “good night” rituals involving a parent. These are just some examples.
Storch, Murphy et al. (2008) assessed 66 children and adolescents with OCD were for OCD symptoms, depression symptoms, and anxiety symptoms. They found that 92% of the children experienced at least one sleep-related problem; 27.3% reported five or more types of sleep-related problems. The total number of sleep-related problems were positively correlated with OCD severity, anxiety severity, and parent ratings of internalizing problems. Significantly, some sleep-related problems decreased following cognitive-behavioral treatment.
A recent meta-analysis by Nota et al. (2015) confirms that OCD is associated with sleep disturbance, but notes that additional research is needed to clarify the effect on sleep duration and sleep timing.
Autism/Asperger’s and Sleep Problems
Sleep problems have long been noted in autistic children, but the impression of the extent and nature of difficulties depends, in part, on what methodology the investigators use to study the problem. Of particular note for educators is a study by Elia et al. (2000), who found that some of the sleep measures were significantly correlated with the child’s functioning. Nonverbal communication showed significant correlation with sleep period time, wakefulness after sleep onset, and total sleep time. Relating to people and activity level items were found to be significantly correlated with rapid eye movement density.
In one of the larger studies using parental reports, Liu et al. (2007) studied 167 ASD children. They found that 86% of the children had at least one sleep problem almost every day. Problems included bedtime resistance (54%), insomnia (56%), parasomnias** (53%), sleep disordered breathing (25%), morning rise problems (45%), and daytime sleepiness (31%).
A study of 52 children with Asperger’s Syndrome also found sleep-related problems (Paavonen, Vehkalahti, et al., 2008). They found that problems with sleep onset and maintenance, sleep-related fears, negative attitudes toward sleeping, and daytime somnolence were more frequent among children with AS than among controls. Short sleep duration was approximately twice as common in Asperger’s as in the control group, while the risk for sleep onset problems was five times as likely. Almost 60% of the children and teens with Asperger’s had a sleep-related problem.
Of note, the sleep hygiene intervention investigated by Hiscock et al. (2015) for youth with ADHD, described above, was also found to be effective for those youth with comorbid ADHD and ASD, with the investigators noting large improvements in sleep and moderate improvements in behavioral functioning at 6-month follow-up.
* Permax® (pergolide) was withdrawn from the market in March 2007 at the request of the FDA due to concerns about heart valve damage.
**Parasomnias include nightmare disorder, sleep terror disorder, sleepwalking disorder, and parasomnias not otherwise specified.