Light Shed on Link Between Depression, Dementia
Researchers deem depression an independent risk factor for dementia
On the other hand, onset of dementia did not seem to be associated with an increase in depression. In fact, the opposite appeared to be true.
"We found that people who are developing dementia did not become more depressed as they developed dementia, they actually became less depressed," Wilson said.
"As people lose their thinking and memory skills, it becomes harder to become depressed and stay depressed," he continued. "Depression depends on a certain continuity of experience that becomes disrupted as you develop dementia. It's left to the rest of us to feel depressed as we watch our loved ones slip into dementia."
However, the researchers found no relationship between depression and dementia-related damage in the brain.
That could mean that treating depression will only stave off a portion of the thinking and memory decline that occurs with age, said Dr. Alan Manevitz, a clinical psychiatrist at Lenox Hill Hospital in New York City.
"Clearly, attending to depression during one's life, just like exercise or eating right, will lead to at least deferring some of the mental decline that comes with aging," Manevitz said. "Also, if you treat depressive symptoms, you may be able to reverse some part of the decline that's related to the depression."
Future research now should pivot to determining exactly how depression influences the risk of dementia, Wilson said.
"We must try to identify structures and functions in the brain that are linked to depression in old age and could help explain depression's link to dementia," he said. "That gives us a better chance of knowing how we should best treat depression in a way that will move the bar and reduce risk of dementia."