BOSTON, July 7 (UPI) -- Those who suffer from depression may have nearly double the risk of developing dementia later in life, U.S. researchers suggest.
Study author Jane Saczynski of the University of Massachusetts Medical School in Worcester, Mass., and colleagues examined data on 949 people with an average age of 79 from the Framingham Heart Study.
They were tested for depressive symptoms and 13 percent were classified as having depression.
For 17 years the study participants were tracked and at the end of the study, 164 people had developed dementia -- 136 with Alzheimer's disease.
Nearly 22 percent of people who were depressed at the start of the study developed dementia compared to about 17 percent of those who were not depressed.
"While it's unclear if depression causes dementia, there are a number of ways depression might impact the risk of dementia," Saczynski said in a statement. "Inflammation of brain tissue that occurs when a person is depressed might contribute to dementia. Proteins in the brain that increase with depression may also increase the risk of developing dementia. Or several lifestyle factors related to long-term depression, such as diet and the amount of exercise and social time a person engages in, could also affect whether they develop dementia."
The findings are published in the journal Neurology.
