Aging: Depression Tied to Alzheimer’s

By NICHOLAS BAKALAR
30 april 2008--A history of depression is associated with an increased risk for Alzheimer’s disease, a new study has found, especially when the depression develops before age 60.
Researchers began the study with 486 men and women who did not have dementia, following them for an average of six years. A total of 134 reported a history of depression. During the study period 44 developed dementia; of those, 33 developed Alzheimer’s.
People who had reported incidents of depression before age 60 were almost four times as likely to develop Alzheimer’s as those who reported no depressive symptoms. Those who reported depression after 60 were more than twice as likely to develop Alzheimer’s as those who did not.
“The better we understand the link between depression and Alzheimer’s, the more insight we will have into the cause of Alzheimer’s,” said Dr. Monique M. B. Breteler, the senior author. “This can allow us to develop more rational therapies.”
Dr. Breteler is a professor of neuroepidemiology at Erasmus Medical Center in Rotterdam, the Netherlands.
The authors acknowledge that they depended on self-reports of depression, and that some people who had suffered mild depression may have been misclassified as having no history of it. Still, the large sample size, prospective design and complete follow-up give considerable strength to the study, published April 8 in Neurology.