U.S. researchers identify prime factors for developing depression

LOS ANGELES, Dec. 17 (Xinhua) -- U.S. researchers have pinpointed the prime factors which put elderly people at greater risk of developing major depression.

The study findings were reported in the December issue of The American Journal of Psychiatry.

People with low-level depressive symptoms, who perceive that they have poor quality social support from other people, and with a past history of depression, were at particularly high risk to develop new major depression within the one-to-four year time period of the study, said researchers at the University of Rochester's Medical Center.

More than 600 people who were 65 years of age or older took part in the study. Only participants without an active diagnosis of major depression were included in the analyses.

Annual follow-up in-person interviews were conducted for up to four years. Information obtained from telephone contacts and annual medical chart reviews supplemented the interviews. Thirty-three participants, or about 5.3 percent, developed an episode of major depression during the study period.

In their analysis, the researchers concluded the "number needed to treat," an epidemiological measure used in determining the effectiveness of a medical intervention, was five. This means the fully effective preventive treatment of five individuals presenting the indicators would prevent one new case of major depression.

Preventive treatments for people in the high-risk group hold promise for providing the greatest health benefit at the lowest cost, the researchers said.

"The present study may inform current clinical practice by fostering early detection and intervention critical to improving patient outcomes for depression," the researchers concluded.

"This is good news, as we in the field are just learning how to prevent depression in particular high-risk groups," said Jeffrey M. Lyness, M.D., professor of Psychiatry at the Medical Center.

"Future work will be able to test whether any of a variety of treatments-perhaps psychotherapy, perhaps medication, perhaps other things such as exercise-will help to prevent depression in persons suffering from the risks we identified in this study."