A team of American scientists has found that people with depression experience a decrease in the volume of elements of the hippocampus, an important part of the brain responsible for memory. A study published in the journal Translational Psychiatry also noted that the problem was worse among those taking antidepressants.
The findings were based on detailed brain scans of more than 2,000 people aged 50 to 90 years. Researchers at the University of Southern California (USC) found that people with diagnosed depression and symptoms of depression had a smaller area of the hippocampus called CA23DG.
The researchers cross-checked the results taking into account patients' weight, frequency of physical activity, and known Alzheimer's disease factors such as tau protein accumulation and amyloid, but the association of CA23DG size was only found with depression. The scientists emphasized that variability in the size of other parts of the hippocampus did not show such an association.
“These findings highlight the importance of paying attention to mental health in the context of a comprehensive approach to healthy brain aging,” Arthur Toga, one of the university’s leading neuroscientists, who took part in the study, said in a USC press release.
He added that further study of the relationship between depression and memory problems in older age will make it possible to more accurately assess the risks of developing dementia in patients and select treatment for them. Scientists have previously known that depression is associated with the risk of developing Alzheimer's disease, the most common form of dementia.
Another author, Danielle Luu, noted that scientists also have to clarify the cause-and-effect relationship in another observation. They noticed in the study that those taking antidepressants had even smaller CA23DG in volume, along with another hippocampal region, CA1.
“Our findings should not be taken as a reason to stop taking prescribed medications or change treatment,” Luu said.
