Many parents report sleep problems in their children with attention-deficit hyperactivity disorder (ADHD), more so than in siblings without ADHD (Marcotte et. al., 1998). Sleep problems include trouble falling asleep and staying asleep, having very restless sleep, or snoring and gasping while sleeping. For many years, research into ADHD has included questions about the prevalence of sleep problems in children with ADHD symptoms.
ADHD affects between five and 10 percent of school age children (Biederman, 2005). Greater awareness of the disorder has led to more research and more effective treatment, but many children still cope with inattentiveness, hyperactivity, impulsiveness, and lack of focus. In the past, the diagnostic criteria for ADHD included “restless sleep,” though the most current guidelines do not include sleep problems. Many health professionals argue that children with ADHD have more sleep difficulties than those without.
Are children with ADHD also suffering from a sleep disorder?
Sleep disorders are a serious health issue. According to the National Institute of Neurological Disorders and Stroke, as many as 40 million Americans suffer from a long-term sleep disorder, such as sleep apnea, insomnia, or restless leg syndrome (NINDS).
Sleep apnea is a pattern of interrupted breathing during sleep, usually caused by pressure on your windpipe as you relax. It’s often associated with obesity or aging, but can also occur in children. Snoring, snorting, and gasping during sleep are common symptoms. The lack of oxygen and constant struggle to breathe during the night leads to continual sleepiness during the day.
Other sleep disorders include restless leg syndrome and periodic limb movement disorder. These conditions cause repetitive jerking movements in the limbs, especially the legs. These motions can wake you up during the night, leading to fragmented, unhealthy sleep. Not getting good sleep results in daytime sleepiness, irritability, depression, and lack of focus.
Sleepiness and ADHD Symptoms
Irritability and lack of focus—hallmarks of ADHD—are also key symptoms of sleep disorders. Plus, sleepiness in children can manifest as hyperactivity. Parents everywhere have seen kids running around frantically when they’re overtired. It may be that the hyperactivity and constant movement of a child with ADHD is actually a sign of “hypoarousal,” or daytime sleepiness. Movement is just the child’s way of staying awake (Golan et. al., 2004).
In several studies of children and daytime sleepiness, researchers found that children with ADHD were much more likely to fall asleep if given the chance to take a nap than children who did not have ADHD symptoms, (Golan, 2004 and Cortese, 2006).
Sleepiness would also explain why stimulant medications are so effective in treating ADHD. More than 80 percent of those diagnosed with ADHD respond well to stimulant medications like methylphenidate (Ritalin, Concerta) or dextroamphetamine (Adderall) (Greenhill et. al., 1999). Just like adults clinging to their coffee to cope with sleepiness, children who do not get quality sleep can improve their attention and focus with stimulants.
Could Sleep Disorders Cause ADHD Behavior?
Some researchers suggest that sleep abnormalities can cause ADHD-like behavior. Large-scale studies using parent and teacher questionnaires have found a correlation between problematic sleep, sleep apnea, and ADHD behavior (Gau, 2006). Studies of children have also found sleep apnea and a high incidence of periodic limb movements (PLM) in those with ADHD (Golan, 2004 and Cortese, 2006). There are even reports that children diagnosed with a sleep disorder and ADHD have had treatment for the sleep disorder and seen a significant improvement in school performance.
It may be that some patients have been misdiagnosed with ADHD, when in fact they have a sleep disorder. But not all children with sleep abnormalities have ADHD behaviors, and not all studies agree on the degree of difference in sleep patterns between children with and without ADHD. PLM and sleep apnea may simply aggravate ADHD behaviors by causing chronic sleepiness.
Another theory is that similar neurochemical pathways cause ADHD and certain sleep disorders. For example, ADHD and periodic limb movement disorder are both associated with low levels of dopamine—an important neurotransmitter in the brain (Prince, 2008 and Ventrungo, 2006). We don’t fully understand how low dopamine levels cause these conditions, but there may be significant overlap. In one study of 34 children with ADHD and 32 without, 15 percent of the ADHD children had PLM disorder, but none of the non-ADHD children did (Golan et. al., 2004).
Larger and more precise studies are necessary, but there’s evidence to suggest that children with ADHD should have their sleep evaluated. If problems like snoring, gasping, or limb movements exist, treating them to allow your child to sleep better may reduce some ADHD symptoms. Talk to your doctor and ask about a sleep study if you think your child may have sleep problems.