Insomnia Can Cause Depression

Actress Eva Longoria poses in the press room after hosting The ALMA Awards in Los Angeles on Thursday, Sept. 17, 2009. (AP Photo/Dan
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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."

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.