ADHD is linked with a variety of sleep problems. For example, one recent study found that children with ADHD had higher rates of daytime sleepiness than children without ADHD. Another study found that 50% of children with ADHD had signs of sleep disordered breathing, compared to only 22% of children without ADHD. Research also suggests that restless legs syndrome and periodic leg movement syndrome are also common in children with ADHD.