P&S Journal: Spring 1996, Vol.16, No.2
Depressed Mood Tied to Alzheimer's
Researchers have found that senior citizens who suffer from depressed mood may have an increased risk of developing dementia, primarily Alzheimer's disease. The study, published in the February issue of Archives of General Psychiatry, emphasizes that it is not yet clear whether depressed mood is an early symptom of Alzheimer's or depressed mood increases susceptibility to Alzheimer's by unknown mechanisms.
"It remains unclear whether a depressed mood is a psychological reaction to memory complaints that occur in the early stages of dementia or whether the depression represents an intermediary factor related to another risk factor yet to be identified," says Dr. D.P. Devanand, associate professor of clinical psychiatry and lead author.
Researchers interviewed 1,070 subjects who reside in the surrounding community, ages 60 and up, establishing a baseline evaluation with a follow-up at one-year intervals for a maximum of five years. At both baseline and follow-up, each subject received a physical and neurological exam and underwent a series of psychological tests to rate memory and concentration and to screen for psychosis and major depression. Subjects who answered yes to the question "Are you sad or depressed?" were considered to have a depressed mood.
Individuals with depressed mood at baseline were three times as likely to have developed dementia, mainly in the form of Alzheimer's disease, by the time of the follow-up evaluation. When the researchers controlled for factors that affect the risk of Alzheimer's disease-memory performance, age, education level, and functional ability-depressed mood still accounted for a two-fold increase in the risk of developing dementia.
"We hope this research will increase attention on the elderly individual who reports feeling sad or depressed to their physicians as it may be an early manifestation of Alzheimer's disease," says senior author and principal investigator of the study, Dr. Richard P. Mayeux, the Gertrude H. Sergievsky Professor of Neurology, Psychiatry, and Public Health. Other authors of the report were Dr. Mary Sano (former Irving Scholar), Dr. Ming-xin Tang, Dr. Stuart Taylor, Dr. Barry J. Gurland, Dr. David Wilder, and Dr. Yaakov Stern. The study was supported in part by federal grants and by the Charles S. Robertson Memorial Gift for Research in Alzheimer's Disease.