Depression is an Independent Risk Factor for Dementia, Researchers

Depression is linked to higher risk of dementia, states a new study.

A latest study by researchers at the Rush University Medical Center in Chicago has found that depression is an independent risk factor for dementia.

"Studies have shown that people with symptoms of depression are more likely to develop dementia, but we haven't known how the relationship works," said study author Robert S. Wilson, PhD, with Rush University Medical Center in Chicago. "Is the depression a consequence of the dementia? Do both problems develop from the same underlying problems in the brain? Or does the relationship of depression with dementia have nothing to do with dementia-related pathology?"

The study was based on data from 1,764 people from the Religious Orders Study and the Rush Memory and Aging Project. Participants were around 77 years old and had no thinking or memory problems at the start of the study.

Participants underwent annual screening for symptoms of depression for about eight years. During the study, 680 people died. Autopsies were performed on 582 of the participants to look for plaques or tangles, which are associated with dementia.

In the study, 922 people or around 52 percent of the participants developed cognitive impairments (MCI), which are mild problems with thinking and remembering things. MCI is considered to be a precursor to Alzheimer's disease. Around 315 people or 18 percent of participants developed dementia.

Researchers found that people with dementia were more likely to have suffered from depression. The team estimates that depression alone could account for four percent of the difference in memory decline that could not be explained by brain damage.

The study shows that although brain damage is an important risk factor for dementia, other problems such as depression can play a vital role in increasing the risk of memory-related problems in old age.

"These findings are exciting because they suggest depression truly is a risk factor for dementia, and if we can target and prevent or treat depression and causes of stress we may have the potential to help people maintain their thinking and memory abilities into old age," Wilson said in a news release.

National Institute on Aging and the Illinois Department of Public Health supported the current research and it is published in the journal Neurology.