How is depression related to dementia?

July 30, 2014

A new study by neuropsychiatric researchers at Rush University Medical Center gives insight into the relationship between depression and dementia. The study is published in the July 30, 2014, online issue of Neurology, the medical journal of the American Academy of Neurology.

"Studies have shown that people with symptoms of are more likely to develop , but we haven't known how the relationship works," said study author Robert S. Wilson, PhD, neuropsychiatrist at the Rush Alzheimer's Disease Center and lead study investigator. "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 current study indicates that the association of depression with dementia is independent of dementia-related brain changes. "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.

The study involved 1,764 people from the Religious Orders Study and the Rush Memory and Aging Project with an average age of 77 who had no thinking or memory problems at the start of the study. Participants were screened every year for , such as loneliness and lack of appetite, and took tests on their thinking and memory skills for an average of eight years. A total of 680 people died during the study, and autopsies were performed on 582 of them to look for the plaques and tangles in the brain that are the signs of dementia and other signs of damage in the brain.

During the study, 922 people, or 52 percent of the participants, developed mild cognitive impairment (MCI), or mild problems with and thinking abilities that is often a precursor to Alzheimer's disease. A total of 315 people, or 18 percent, developed dementia.

The researchers found no relationship between how much damage was found in the brain and the level of people had or in the change in depression symptoms over time.

People who developed were more likely to have a higher level of symptoms of depression before they were diagnosed, but they were no more likely to have any change in symptoms of depression after the diagnosis than people without MCI. People with dementia were also more likely to have a higher level of depression symptoms before the dementia started, but they had a more rapid decrease in depression symptoms after dementia developed.

Having a higher level of depression symptoms was associated with more rapid decline in thinking and , accounting for 4.4 percent of the difference in decline that could not be attributed to the level of damage in the brain.

Explore further: Late-life depression associated with prevalent mild cognitive impairment, increased risk of dementia

Related Stories

About one-quarter of patients with MCI progress to dementia

March 12, 2014

(HealthDay)—About 22 percent of patients with mild cognitive impairment (MCI) progress to dementia within three years, and depression symptoms modify the prognosis, according to a study published in the March/April issue ...

Recommended for you

Rat brain atlas provides MR images for stereotaxic surgery

October 21, 2016

Boris Odintsov, senior research scientist at the Biomedical Imaging Center at the Beckman Institute for Advanced Science and Technology at the University of Illinois in Urbana-Champaign, and Thomas Brozoski, research professor ...

Imaging technique maps serotonin activity in living brains

October 20, 2016

Serotonin is a neurotransmitter that's partly responsible for feelings of happiness and for mood regulation in humans. This makes it a common target for antidepressants, which block serotonin from being reabsorbed by neurons ...

Overcoming egocentricity increases self-control

October 19, 2016

Neurobiological models of self-control usually focus on brain mechanisms involved in impulse control and emotion regulation. Recent research at the University of Zurich shows that the mechanism for overcoming egocentricity ...

Exercise may help ward off memory decline

October 19, 2016

Exercise may be associated with a small benefit for elderly people who already have memory and thinking problems, according to new research published in the October 19, 2016, online issue of Neurology, a medical journal of ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.