Researchers looked at a large pool of cases over a long period of time to determine whether people with depression were more likely to have dementia later in life.
This raises questions about properly treating depression earlier in life to prevent dementia.
"Talk to your doctor if you’re experiencing depressive symptoms."
Deborah E. Barnes Ph.D., M.P.H., associate professor of psychology at the University of California, San Francisco and the San Francisco Veterans Affairs Medical Center, led a study to gauge the association between depression and dementia.
When Barnes’ team looked at Alzheimer disease and vascular dementia separately, they noticed that the patients with only late-life depressive symptoms were twice as likely to have Alzheimer disease. Those patients with mid-life and late-life depressive symptoms were three times as likely to have vascular dementia.
For the study pool researchers looked at 13,535 people that had been in the same health care coverage system since 1964. First they looked at those who had depressive symptoms in mid-life, from 1964-1973, and then those who had them in late life, from 1994-2000. The final data was collected in retrospect from 2003-2009, when the average age of those in the study was 81.1 years of age, give or take 4.5 years.
Fourteen and one-tenth percent of the pool presented depressive symptoms only in mid-life, 9.2 percent of the pool only in late life and 4.2 percent experienced depression in both mid- and late-life. The retrospective data found that 22.5 percent were eventually diagnosed with dementia, 5.5 percent with Alzheimer disease and 2.3 percent with vascular dementia.
Researchers concluded that late-life only depression might be an associated symptom with the early stages of Alzheimer disease; however, earlier life and recurring depression may increase the risk of vascular dementia.
Authors state there is good news to focus on, “These findings have important public health implications because they raise hope that adequate treatment of depression in midlife may reduce dementia risk in late life.”
This study will be published in the Archives of General Psychiatry, May 2012. Funding for this study was provided by the Brain and Behavior Research Foundation and the National Institutes of Health and Kaiser Permanente Community Benefits, no conflicts of interest were reported.