Feb. 13, 2002 -- Depression may not only affect the mental health of older adults, but it could put their physical health at risk too. A new study shows that chronic depression --even mild cases -- may compromise their ability to fight off infection and disease.
Researchers say this and other recent studies suggest symptoms of depression may worsen and speed up the gradual weakening of the immune system that occurs with aging.
The study, which is published in this month's Journal of Abnormal Psychology, tested the ability of 78 older adults (average age 73 years) to generate enough white blood cells to fight off an infectious agent. Researchers found those with chronic mild depression had a poorer immune response at the start of the study as well as at the follow up 18 months later. In addition, the older a person was, the worse their immune system response was to viruses and bacteria.
With current estimates showing that up to 57% of older adults suffer from some form of chronic depression at some point later in life, researchers say aggressive efforts are needed to identify and treat depressed seniors.
"Although the prevalence of depressive symptoms may be high in older adults, these symptoms are often undetected and untreated," write the authors. "Our findings suggest that detection and treatment of such symptoms may be important for optimal immune function in older adults."
And even mild depression deserves treatment, the researchers say. In fact, of the 22 patients who reported significant symptoms of depression at the beginning and end of the study, fewer than half met the formal diagnostic criteria for depression. That is, they wouldn't be considered truly "depressed" by current medical standards.
"In this study, it seems that it is the length of time of the depression, not the severity, that is affecting a person's immunity," says study author Lynanne McGuire, PhD, of Johns Hopkins School of Medicine in a news release.
Previous research has shown that strong social support can have a positive effect on health, and the authors point out that a lack of social support, or reluctance to seek social support, among depressed seniors may also have contributed to the immune decline and negative health effects found in this study.