Insomnia has long been thought of as a symptom of depression, but new research shows it may actually trigger the mental disorder.

In one study, depressed seniors with insomnia were 17 times more likely to remain depressed after a year than patients who were sleeping well. The findings were presented Tuesday at the 19th Annual Meeting of the Associated Professional Sleep Societies in Denver.

In a separate study, seniors with insomnia and no history of depression were six times more likely to experience an episode of depression as seniors without insomnia. The association was strong for women and for people who suffer from a particular insomnia pattern that awakens a person repeatedly during the night.

Both studies were conducted by researchers from the University of Rochester Sleep and Neurophysiology Research Laboratory. Lab director Michael Perlis, PhD, tells WebMD that while the research focused on seniors, the findings could apply to anyone with chronic insomnia.

“The assumption has been that if depression is well treated, the insomnia will go away, but this is not the case,” Perlis tells WebMD. “It is increasingly clear that you can’t ignore chronic insomnia [in patients with depression]. You have to treat it.”

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Other Research

In another study, researchers report that patients with depression and sleep problems treated with the antidepression drug Prozac and the insomnia drug Lunesta got better quicker than those treated for depression only.

Perlis and colleagues are also conducting depression studies to determine if treating insomnia reduces the severity or lengthens the time between episodes of depression.

They are also examining the impact of insomnia treatment on pain management in patients with chronic back pain. The research is being funded by a $2.3 million grant from the National Institutes of Health.

He says there is growing evidence linking chronic insomnia with other common ailments, including high blood pressure and type 2 diabetes. He defines chronic insomnia as a troubling a sleep disturbance lasting more than three months.

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Treating Insomnia

So which treatments work best?

Perlis says that insomnia of a few days duration should be ignored as much as possible.

“If you don’t compensate in any way by changing your habits, the ship is likely to right itself,” he says. “But if you change your habits, by either sleeping later, going to bed earlier, or forcing yourself to stay in bed when you’re wide awake, you are laying down the foundation for a more chronic disorder.”

If the insomnia persists beyond five days or so, it should definitely not be ignored, Perlis says. He recommends trying one of the new generation of prescription hypnotic sleep drugs, such as Ambien, Sonata, or Lunesta, or trying behavioral therapy that specifically targets insomnia.

In a report issued last week, an expert panel convened by the National Institutes of Health endorsed the behavioral therapy approach. Panel members also expressed concern about the widespread use of over-the-counter and prescription medications that have no clear benefit in the treatment of insomnia, such as antidepressants and antihistamines.

While conceding that the new generation of insomnia drugs has fewer and less severe side effects than other sleep medications and shows promise for long-term use, the panel concluded that long-term safety has not been proven.

The experts noted that relaxation training combined with therapy targeting erroneous, anxiety-producing beliefs about sleep loss has been shown to be an effective treatment for insomnia.

“We know that patients can struggle for years with insomnia, and we know that they use a variety of over-the-counter and prescription drugs to deal with it,” panel chairman Alan Leshner, PhD, says, in a news release. “Unfortunately, we found insufficient evidence to recommend most of these treatments for long-term use. There’s a clear need for more research to fill this gap.”

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By Salynn Boyles, reviewed by Brunilda Nazario, MD

SOURCES: 19th Annual Meeting of the Associated Professional Sleep Societies, Denver, June 18-23, 2005. Michael Perlis, PhD, director, University of Rochester Sleep and Neurophysiology Research Laboratory. Krystal, A., presentation, APSS meeting. National Institutes of Health Panel Report on the Treatment of Chronic Insomnia, June 15, 2005. Alan Leshner, PhD, chief executive officer, American Association for the Advancement of Science; chairman, NIH panel on insomnia treatment.