The study followed 7,207 adults who enrolled in the Health and Retirement Study, an ongoing national prospective study of health, income, and wealth, in 1992, when they were aged 50 to 61. The authors found that by 2006, 45 percent of the 877 participants who reported significant depressive symptoms in 1992 had persistent difficulty with mobility or activities of daily living, versus 23 percent of the non-depressed participants.
The link between depression and increased risk of later disability remained significant even after the researchers adjusted for age, gender, physical condition, health status, socioeconomic status, and other factors.
The study appears in the online Early View section of the “Journal of the American Geriatrics Society.”
Lead author Kenneth E. Covinsky, MD, MPH, a geriatrician at SFVAMC, says that the study was not designed to examine the reasons for the link.
It is not clear, he says, whether treating middle-aged depression with anti-depressive medications will help prevent later disability. “It might make just as much sense to think about mechanisms by which depressed people might become physically disabled,” he says. “For example, we know that people with depression are socially isolated, which in turn compromises their ability to live independently. They are also less physically active, which has a direct effect on health. So we might want to include interventions that improve social functioning and level of physical activity.”
Covinsky, who is also a professor of medicine at UCSF, likens such a program to preventive treatment for heart disease. “Much as we now look at heart disease risk factors over a period of 10 to 20 years, and start treating high-risk patients years in advance, we should start looking at risk of late-life disability long before it actually occurs,” he says. “We don’t do that now – instead we wait until someone has actually become disabled before we think about what to do for them.”
Co-authors of the study are Kristine Yaffe, MD, Karla Lindquist, MS, Elena Cherkasova, BS, and Edward Yelin, PhD, of SFVAMC and UCSF, and Dan G. Blazer, MD, PhD, of Duke University, North Carolina.
The study was supported by funds from the National Institute on Aging that were administered by the Northern California Institute for Research and Education. The Health and Retirement study is sponsored by the NIA.
NCIRE – The Veterans Health Research Institute – is the largest research institute associated with a VA medical center. Its mission is to improve the health and well-being of veterans and the general public by supporting a world-class biomedical research program conducted by the UCSF faculty at SFVAMC.
SFVAMC has the largest medical research program in the national VA system, with more than 200 research scientists, all of whom are faculty members at UCSF.
UCSF is a leading university dedicated to promoting health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care.