Depression, Cognitive Problems Linked with Brain Shrinkage in Old People

Brains of old people, who suffer from depression or cognitive impairments, age faster than the brains of other happy senior citizens, a new study has found.

Previous research has shown that depression is associated with impaired cognitive performance. The study shows that old people with depression are at a greater risk for accelerated brain aging.

The study is published in the journal Molecular Psychiatry.

Meryl A. Butters - Ph.D., associate professor of psychiatry, Pitt School of Medicine - said that elderly people with depression are more likely to suffer from dementia. However, research hasn't been able to establish why a treatable mood disorder leads to a neurological problem.

The present study was based on a small set of 80 older adults who had received treatment for depression. In this group, 36 people had mild cognitive impairments and 44 had normal cognitive function.

"Our study represents a significant advance because it provides a more comprehensive and integrated view of the neurobiological changes related to mild cognitive impairment in late-life," she said. "Better understanding of the neurobiology of cognitive impairment in depression can provide new targets for developing more specific treatments, not only for its prevention and treatment, but also for its down-stream negative outcomes, including the development of dementia and related disorders."

For the study, the researchers looked at levels of 242 proteins in the blood samples of the participants. These proteins are involved in the biological pathways linked to heart diseases, cancer and psychiatric problems.

Brain scans of the participants were also taken to look at signs of brain shrinkage. The team even accounted for beta-amyloid protein, which is associated with plaques - a classic marker for Alzheimer's disease.

The researchers found that the MCI group had differences in biological activity of 24 proteins that regulate the pathways linked to inflammation and immune system.

People suffering from mild cognitive problems were more likely to suffer from cerebrovascular diseases such as small strokes, scientists said.

"If you take these results altogether, they suggest that people with depression and cognitive impairment may be more vulnerable to accelerated brain aging, which in turn puts them at risk for developing dementia," Dr. Butters said in a news release. "Ultimately, if we can understand what happens in the brain when people are depressed and suffer cognitive impairment, we can then develop strategies to slow or perhaps stop the impairment from progressing to dementia."