Through the years, a growing number of fidgety, forgetful, and unfocused children have been diagnosed with attention deficit hyperactivity disorder, or ADHD. The Centers for Disease Control and Prevention reports that more than 5 million children ages 3 to 17 have been diagnosed with the condition, making it one of the most common mental disorders in children and adolescents. This has even prompted declarations of an ADHD epidemic in America. Recent research, though, suggests that a child's sleep patterns could partly be to blame.
"Sleep disorders may contribute to behaviors that resemble ADHD during the day," says Kevin Smith, a pediatric psychologist at Children's Mercy Hospitals and Clinics in Kansas City, Mo. A study published in March in Pediatrics analyzed more than 11,000 children over a period of six years, beginning at 6 months of age, and revealed that children suffering from sleep-disordered breathing—including snoring, breathing through the mouth, and apnea, where the child seems to stop breathing for several seconds at a time—had a higher incidence of behavioral and emotional issues such as hyperactivity, aggressiveness, depression, and anxiety. In fact, they were 50 to 90 percent more likely to develop ADHD-like symptoms than were normal breathers. And those children who suffered most severely from all three sleep-disordered breathing behaviors at around age 2 and a half had the highest risk for hyperactivity.
A lack of sleep can damage brain neurons, particularly in the prefrontal cortex region, says Karen Bonuck, lead author and professor of family and social medicine at the Albert Einstein College of Medicine in New York. This may be due to a decrease in oxygen and an increase in carbon dioxide levels; interference with sleep's restorative processes; and a disruption in the balance of cellular and chemical systems. What can result is inattentiveness, hyperactivity, and impulsivity—the classic trademarks of ADHD. When the disorder is suspected in a child, "nighttime sleep patterns should be reviewed with the primary care doctor," says Bonuck. "Parents may even wish to video or audio tape the problematic behavior as a first step."
A separate study released in June examined the long-term impact of obstructive sleep apnea (OSA)—where the airway has collapsed or is blocked during sleep—in teenagers, and it revealed similar results. Researchers from the University of Arizona assessed the behavior of 263 older children, some with OSA and some without, during two different periods of their life, approximately five years apart. "Those with persistent OSA had particular problems with hyperactivity and aggression as well as with social interactions and leadership skills," says Michelle Perfect, lead author and assistant professor of psychology at the University of Arizona. "Several studies point to higher rates of OSA in youth with ADHD," says Perfect, "though depending on the definition of OSA over the years, some data have not supported such findings."
One study published in Pediatrics in 2006 found that among a group of 78 children scheduled to have their tonsils and adenoids removed to alleviate OSA, 28 percent had been diagnosed with ADHD. A year after surgery, half of them were declared to no longer have the disorder. Says Perfect: "It's not known if children who have OSA are misdiagnosed with ADHD, but school personnel and clinicians should consider an evaluation for sleep-disordered breathing when a child exhibits problems with attention and hyperactivity. At the very least, OSA symptoms could exacerbate ADHD symptoms."
If there is a misdiagnosis of ADHD, this can be problematic when one considers the fact that medications used to treat ADHD, like Vyvanse and Ritalin, are stimulants and can cause insomnia. In September of last year, the National Institutes of Health and the Agency for Healthcare Research and Quality reported that the prescribed use of stimulant medications for ADHD in children ages 6 to 12 rose from 4.2 percent in 1996 to 5.1 percent in 2008. For children ages 13 to 18, that rate increased from 2.3 percent in 1996 to 4.9 percent in 2008.