Childhood Hyperactivity Linked to Problems With Sleep
April 17, 2000 (New York) -- Many parents of children with attention deficit
hyperactivity disorder (ADHD) report that their child acts up at bedtime or has
problems sleeping. A new study shows that the problem may actually be related
to the child's "internal clock" that determines what time the child
falls asleep each night, according to a study in the April issue of the
Journal of the American Academy of Child and Adolescent Psychiatry.
Children with ADHD are typically inattentive, easily distractible,
impulsive, restless, and hyperactive. In recent years, parents have reported
that these children also have sleep problems, but few studies have looked into
the possible connection between sleep and ADHD.
Ronald D. Chervin, MD, tells WebMD that the new study gives doctors and
parents a better idea of what may be going on. "These disturbances have
been widely reported for a long time," says Chervin, who is assistant
professor of neurology, University of Michigan, Ann Arbor, and acting director
of the Sleep Disorders Center.
Chervin describes the sleep problems of ADHD children as having trouble
going to sleep or refusing to go to bed. They often have problems falling
asleep and when asleep, do a lot of tossing and turning. "This study is
showing that the time at which the child went to sleep varied within a two- to
three-hour interval for the ADHD child, whereas it varied only about 40 minutes
[for the normal] child."
The researchers used a watch-like device to measure movements during the
night and record important data about sleep. The study consisted of 38
10-year-old Israeli boys who had ADHD and 64 boys of the same age who did not
have ADHD. All boys in the study wore the watch-like monitoring device for five
consecutive nights while they slept. Their parents were questioned about
behavior problems, and the children themselves completed daily sleep logs with
information about bedtimes, waking times, quality of sleep, and amount of
The sleep monitoring took place on school nights to eliminate any variations
in sleep schedules that might be caused by weekends or holidays.
Study author Reut Gruber, PhD, of the National Institute of Mental Health in
Bethesda, found that while the two groups of children had no real differences
on many aspects of sleep, they differed significantly in terms of the times
they fell asleep on each of the five nights.
For example, while a typical boy with no ADHD consistently fell asleep each
night between 9:30 p.m. and 10:30 p.m., the typical ADHD boy fell asleep at 10
p.m. one night, 9 p.m. the next night, 11 p.m. the following night, midnight
the next night, and 10 p.m. the following night.