People with insomnia and a psychiatric disorder are less likely to get sleep medication and thus may have increased risk for worsening of disorders such as depression, anxiety, or other mood disorder, according to an article in the January issue of the Journal of Medical Economics.

"Insomnia can cause you to have anxiety and depression, and depression and anxiety can cause you to have insomnia. It's a chicken-and-egg type of story. But research has shown that if one of the conditions is left untreated it can exacerbate the other condition," said senior study author Rajesh Balkrishnan, the Merrell Dow professor of pharmacy at Ohio State University.

An estimated 20 percent of Americans have occasional sleep problems, with about 1 in 10 suffering from chronic insomnia.

"This research highlights the need to take into account that many patients who see their doctors with complaints of insomnia also have a psychiatric condition. But the presence of those mental conditions should not preclude them from being appropriately treated for their insomnia," he said.

The study is published in the January issue of the Journal of Medical Economics.
Balkrishnan and colleagues collected data from the National Ambulatory Medical Care Survey, which tracks Americans' annual outpatient medical visits. The researchers identified 5,487 physician visits by patients with insomnia between 1995 and 2004, which was calculated to represent about 161 million U.S. patients over that 10-year period.

According to the analysis, an estimated 6.5 million Americans who saw a doctor for insomnia also were diagnosed with a mental health disorder. Of the visits examined, 38 percent of patients with insomnia were diagnosed with at least one other condition, and at least 4 of every 10 of those accompanying conditions related to mental health. The most common additional condition was anxiety (15.6 percent), followed by episodic mood disorders (14.9 percent), hypertension (10.1 percent), depression (7 percent) and diabetes (3.5 percent).

The study showed that insomnia patients with mental health disorders were 36 percent less likely to receive medication for their sleeping problems than were patients without the mental health diagnosis. Those with anxiety were the least likely to receive a sleep aid, with a 45 percent decreased likelihood of receiving medication for insomnia compared with patients without anxiety.

According to the analysis, patients visiting psychiatrists had two times higher odds of receiving medication for insomnia than patients visiting family practice or internal medicine physicians. The study showed that 33 percent of patients with insomnia saw family practice or internal medicine physicians, 30 percent visited psychiatrists and 9 percent went to neurologists.

The study identified other factors associated with insomnia medication prescribing patterns - for example, older and established patients were more likely to receive insomnia medications than were younger patients or those seeing the doctor for the first time. But Balkrishnan said a clear theme emerged from the analysis.

"There is a divide in who gets appropriate medication and who is not appropriately medicated," he said. "It might not be happening willfully, but it points to a knowledge gap between different types of physicians and the need to develop widely accepted treatment guidelines. And the guidelines should be ratified by essentially all physicians treating the condition."