March 3, 2003 -- A child who is overtired or snores loudly during sleep may display some of the same behavioral problems caused by attention deficit-hyperactivity disorder (ADHD). A new study suggests that common sleep-disordered breathing such as snoring may lead to hyperactive behavior that easily might be mistaken for a mild case of ADHD.
But the study also shows that many parents of children with ADHD may be overestimating their children's sleep difficulty. Researchers say parents often complain their children with ADHD have difficulty sleeping, but researchers found few of these children who were studied in a sleep lab actually had sleeping disorders.
Researchers say their findings suggest that doctors should be aware that children who display more severe hyperactive behavior -- but do not meet the standard criteria for ADHD -- may actually suffer from a sleep disorder or other problems sleeping that merit evaluation.
The findings appear in the March issue of Pediatrics. Researchers surveyed more than 5,000 parents of children between the ages of 5 and 7 about their children's sleeping habits and whether they believed their children to be hyperactive or have ADHD.
About 12% of the parents reported their child frequently snored loudly in their sleep, and another 7% said their children were hyperactive or had been diagnosed with ADHD. Of these, more then three-quarters of the children were boys.
Sleep studies were conducted in the children whose parents reported they had ADHD symptoms. The children were later classified as having significant, mild, or no symptoms and were compared with children without ADHD symptoms.
Researchers found more than a quarter of the children with mild symptoms suggestive of ADHD suffered from sleep apnea, a sleeping disorder in which breathing is interrupted, and snoring, more than other children.
They also found that in children with severe symptoms, REM (rapid eye movement) sleep was disturbed, which appeared to affect daytime behavior. But this group of children did not suffer from sleep-disturbed breathing more than children without ADHD.
Parents of children with mild or moderate symptoms suggestive of ADHD were also twice as likely to say their children had difficulty falling asleep or were unwilling to fall asleep.
Overall, researchers found 77% of the children with significant symptoms were considered to have significant sleep problems by their parents. But when these children were observed in a sleep clinic, only 20% had diagnosable sleeping disorders.
Researcher David Gozal, MD, of the University of Louisville, and colleagues say other studies have also found that many parents of ADHD children say their child suffers from sleep disturbances. But this study suggests that those findings may be based more on parental perceptions that actual sleeping disorders.
In addition, they say that although sleep apnea may cause mild symptoms like those of ADHD, this study shows that it does lead to more severe behavioral problems.
SOURCE: Pediatrics, March 2003.