Insomnia Can Trigger Depression, Study Shows

June 24, 2005 -- 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.