Public Release: 

Penn Researchers First To Link Differences In Brain Structure To Minor Depression In The Elderly

University of Pennsylvania School of Medicine

Minor depression in late life is often trivialized and left untreated, in part because scientists have yet to establish a biological basis for the disorder. Now, in the first report of its kind, researchers at the University of Pennsylvania Medical Center have demonstrated that the prefrontal lobe in elderly patients with minor depression is significantly smaller than in non-depressed control subjects. (The prefrontal lobe is the region in the brain that has historically been associated with behavior and emotional states.) The magnetic resonance imaging (MRI) study appears in the May 15 issue of the Archives of Neurology.

Affecting as many as one in five people age 65 and older, minor depression is more prevalent -- yet less recognized -- than major depression in elderly populations. Symptoms such as low mood, fatigue and loss of interest can have adverse affects on well-being and productivity, and may be a risk factor for major depression. Often thought to be a response to unfortunate life circumstances, the neurobiologic basis of minor depression has received little scrutiny.

The study was comprised of 18 elderly patients who had experienced minor depression for the first time in late life and 31 age-comparable non-depressed controls. None of the study subjects had clinical evidence of dementia or any other brain disorder, and both groups were comparatively healthy. Using MRI, the Penn investigators found significantly smaller prefrontal lobe volume in the group with minor depression, but similar total brain volumes in both groups. "Despite the relatively modest sizes of the study groups," says lead author Anand Kumar, MD, director of the Mood and Memory Disorders Program, "the consistent finding of prefrontal atrophy has important neurobiologic implications for minor depression."

Dr. Kumar likens mood disturbance to other common illnesses that affect the elderly, like diabetes and heart disease. "Major depression is analogous to a heart attack: it's critical enough that it gets everyone's attention," he explains. "Minor depression is like angina: it's much more common, and easier to disregard. But without treatment, the milder forms of these illnesses may lead to more severe problems."

Antidepressant medications, combined with psychological and social intervention, may relieve late life minor depression. "My colleagues and I hope that family members, caretakers and primary care doctors will recognize the signs of minor depression and encourage seniors get the help they need," says Dr. Kumar. "If fatigue, the "blues or crying spells persist for more than a few weeks, appropriate diagnosis and treatment may ease the symptoms and significantly improve the patient's quality of life."

The study was supported by a grant from the Charles A. Dana Foundation and a Clinical Mental Health Academic Award from the National Institutes of Mental Health.

The University of Pennsylvania Medical Center's sponsored research ranks fifth in the United States, based on grant support from the National Institutes of Health, the primary funder of biomedical research in the nation -- $149 million in federal fiscal year 1996. In addition, for the second consecutive year, the institution posted the highest growth rate in its research activity -- 9.1 percent -- of the top ten U.S. academic medical centers during the same period.

Penn news releases are available to reporters by direct e-mail, fax, or U.S. mail, upon request. They are also posted electronically to EurekAlert! (http://www.eurekalert.org), an Internet resource sponsored by the American Association for the Advancement of Science, and to the SciNews-MedNews section of the Journalism Forum, a component of CompuServe. Additionally, they are distributed via the electronic news service Quadnet.

Editor's Note: For an interview or more information, call Dr. Kumar at (215) 662-7426.

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