The ADHD Factor
Sleep lab studies suggest links between ADHD and sleep problems. For example, kids with ADHD tend to have high rates of medically caused sleep disorders like restless legs syndrome (RLS), characterized by an urge to move, or even tingling or painful sensations when legs remain still, and periodic limb movement disorder (PLMD), in which leg muscles repeatedly contract at night, temporarily waking the child. One study from the University of Illinois at Urbana-Champaign looked at 69 children diagnosed with ADHD and found that 26% suffered from PLMD, a disorder that's rare in the rest of the population.
In another study, conducted by Ronald D. Chervin, M.D., director of the University of Michigan Sleep Disorders Center in Ann Arbor, it was found that habitual snoring, a symptom of OSA, occurred in 33% of kids ages 2 to 18 diagnosed with ADHD, compared to 9% of a control group. "Sleep disorders won't explain the majority of behavioral problems in children, but even if they affect a only a smaller fraction of hyperactive kids, it's still a lot of people," he says.
Yet sleep habits are not typically considered when kids are assessed for behavioral or learning issues. "Absolutely every child who's being evaluated for academic problems, learning problems, behavioral problems, or ADHD should be screened for sleep issues," says Dr. Owens.