Depression Linked to Higher Risk of Alzheimer's Dementia
Depressed study subjects had 72 percent higher risk of dementia, 76 percent higher Alzheimer's risk
TUESDAY, July 6 (HealthDay News) -- Depression is associated with a higher risk of dementia and Alzheimer's disease in older people over long-term follow-up, according to research published in the July 6 issue of Neurology.
Jane S. Saczynski, Ph.D., of the University of Massachusetts Medical School in Worcester, and colleagues analyzed data from 949 dementia-free participants from the original Framingham Heart Study cohort who were tested for depressive symptoms from 1990 to 1994 using the Center for Epidemiologic Studies Depression Scale (CES-D). Of the group, 13.2 percent were classified as depressed.
The researchers found that 21.6 percent of subjects who were depressed at baseline developed dementia, compared to 16.6 percent of subjects who were not depressed. Those who were depressed had an increased risk of both dementia (hazard ratio, 1.72) and Alzheimer's disease (hazard ratio, 1.76). Each 10-point increase on the CES-D was linked to a 46 and 39 percent higher risk of dementia and Alzheimer's, respectively.
"The association between late-life depression and cognitive impairment does not appear to be spurious. However, there is insufficient evidence at present to support the hypothesis that depression has a direct causal relationship with subsequent dementia. Only a future mechanism of disease study with a biologic marker for depression can clearly identify which of the four hypotheses is most pertinent in explaining the link between depression and dementia/mild cognitive impairment," writes the author of an accompanying editorial.
A study co-author disclosed financial relationships with Forest Laboratories Inc. and Takeda Pharmaceutical Company Ltd.