Sleep disorders are associated with numerous health consequences. Now, a new study shows that a link may exist between sleep difficulties and attention deficit disorder (search) in adults.

People with sleep disorders may also have mood disorders, neuromuscular diseases, and other problems, according to Clifford Risk, MD, PhD, director of the Marlborough Center for Sleep Disorders in Marlborough, Mass.

Approximately 30 million Americans suffer from obstructive sleep apnea (search). The most common complaints are loud snoring, disrupted sleep, and excess daytime sleepiness. 

Obstructive sleep apnea causes repetitive blockage of the airways during sleep. The muscles that keep the airways open collapse and air cannot get to the lungs. Medical conditions such as cardiovascular disease, high blood pressure, and diabetes are associated with obstructive sleep apnea. Smoking is also linked to this sleeping disorder.

The researchers studied 34 people with obstructive sleep apnea. Nearly half of the group (16 people) showed signs of possible or probable attention deficit disorder.

All the participants were then given continuous positive airway pressure (CPAP), the most widely used treatment for obstructive sleep apnea.

CPAP uses a machine that delivers forced air through a mask over the nose (and sometimes also the mouth) to keep the airway open.

After CPAP treatments, the participants' daytime sleepiness score improved. Average scores dropped from 12 to around three on a scale of 0-24, with 24 being the most severe rating. The same group reported improvement in attention deficit scores from 17 to a score of 10, a significant change according to the researchers.

In addition, nine of the 16 patients with possible or probable attention deficit disorder, based on having moderate to severe attention deficits scores, improved their attention scores after CPAP.

In an interview with WebMD, Risk says sleep apnea is "highly correlated" with attention deficit disorder and that treating apnea can improve attention deficit. However, some apnea patients may continue to have attention deficit problems after CPAP due to "anxiety, depression, or other disorders," he says.

Risk and colleagues also studied smaller groups of people with insomnia.

"For those with severe insomnia, we found a high prevalence of anxiety, depression, and neuromuscular disease, such as chronic fatigue, fibromyalgia, and neurological disorders," he says.

In a small study of six to eight adolescents, Risk found that insomnia was sometimes accompanied by learning disorders, anxiety disorders, and attention deficit disorder.

Sleep disorders and other health problems can go hand in hand.

"Insomnia can be due to anxiety, depression, learning disorders, and neuromuscular diseases," says Risk. "It's also the Holy Grail for getting them better."

Risk presented his findings in Seattle at CHEST 2004, a meeting of the American College of Chest Physicians.

By  Miranda Hitti, reviewed by  Brunilda Nazario, MD

SOURCES: Clifford Risk, MD, Marlborough Center for Sleep Disorders. CHEST 2004, Seattle, Oct. 23-28, 2004. WebMD Medical Reference from Healthwise: "Sleep Apnea: Treatment Overview." WebMD Medical Reference from Healthwise: "Continuous Positive Airway Pressure (CPAP)."  News release, American College of Chest Physicians.