Restless nights up senior depression risk

LOS ANGELES, Oct. 1 (UPI) -- Sleeplessness can be annoying and unhealthy, but for the elderly who have suffered depression it can mean another bout of depression, researchers said.

The study, to be published in the American Journal of Psychiatry, looked at 351 adults age 60 and older, of which 145 had a prior history of major or non-major psychological depression that was in full remission, while 206 had no prior history of depression or other mental illness.

The participants were assessed at four different times over a two-year period for depressive episodes, depressive symptoms, sleep quality and chronic medical disease.

University of California, Los Angeles, Professor of Psychiatry Dr. Michael Irwin and colleagues found that of the subjects with prior depression, 23 had a relapse, compared with only one person in the group without prior mental illness.

With the first group, researchers were able to predict depression recurrence based on the individuals' sleep disturbance. Irwin noted that this association was established independently of other depressive symptoms, chronic medical disease or any use of antidepressants.

The study, Irwin said, is the first to demonstrate that sleep disturbances act as an independent risk factor for depression recurrence in older adults.