Over the course of the study, 269 (35.7 percent) of the participants were depressed at some point. Of those, 48 (17.8 percent) remained depressed during two consecutive time periods, 30 (11.2 percent) at three time points, 17 (6.3 percent) at four points and 12 (4.5 percent) at all five. More women than men were depressed at each 18-month follow-up and women were more likely than men to experience depression at subsequent time points. "Adjusting for other demographic characteristics, women had a higher likelihood of transitioning from non-depressed to depressed and a lower likelihood of transitioning from depressed to non-depressed or death," the authors write.

The findings were consistent over the four time intervals, providing strong evidence that depression is more persistent in older women than older men, the authors note. This is surprising, because women are more likely to receive medications or other treatment for depression. "Whether women are treated less aggressively than men for late-life depression or are less likely to respond to conventional treatment is not known but should be the focus of future research," the authors write. "In addition, nearly 40 percent of the depressed participants in this study were depressed during at least two consecutive time points, highlighting the need to initiate and potentially maintain antidepressant treatment after resolution of the initial depressive episode."
(Arch Gen Psychiatry. 2008; 65[2]:172-178. Pre-embargo to the media at www.jamamedia.org.) van Available

Note: van Editor This study was supported by grants from the National Institute on Aging. The study was conducted at the Yale Claude D. Pepper Older Americans Independence Center. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc..