Time with freinds and family seems protective against depression and dementia.

RODALE NEWS, EMMAUS, PA—Our brains and our bodies are so intricately linked that mental disorders like depression have a profound impact on the rest of our health. Depression has been linked to an increased risk of diabetes and heart disease, and it could be as bad for your health as smoking. But what does it do to your brain? In last week's online edition of Neurology, a 17-year-long study demonstrated some of the most profound evidence to date that depression is strongly related to other mental diseases, namely dementia and Alzheimer's disease. And the effects don't go away when someone feels they are "cured" of it.

THE DETAILS: The researchers used participants of the Framingham Heart Study, a group of people whom medical scientists have been studying since 1948. They narrowed down the original 5,209 participants to a group of 949 adults, average age 79, who were free of dementia at the start of the study. Of the patients diagnosed with depression at the start of the study, tests given about nine years later showed that 21.6 percent developed dementia, compared with just 16.6 percent of people who were not depressed. The researchers also saw a 50 percent increase in the risk of developing dementia with each 10-point increase in score on depression tests administered at the start of the study. The risks were similar for Alzheimer's disease, for which there was a 40 percent increase in risk for each 10-point increase in depression score. For both dementia and Alzheimer's disease, depressed adults were 1.5 times more likely to develop one of the two diseases than nondepressed adults.

WHAT IT MEANS: "Depression needs to be taken very seriously," says the study's lead author Jane Saczynski, PhD, assistant professor of medicine at the University of Massachusetts Medical School. "It's a very serious medical condition that is known to be related to other medical conditions." But what her study can't show, she says, is whether depression causes dementia, whether it's a risk factor, or whether people who have depression have some other sort of chemical imbalance that turns up as dementia later in life. But it's becoming more and more obvious that the two are linked.