Mental Health

Depression Can Harm Memory, Lead To Smaller Brain Volume In Older Adults

Depression is known to negatively affect mood, often reducing the quality of life. In a new study, researchers found that older adults with depressive symptoms may have memory problems as well as structural changes in their brain.

"With as many as 25% of older adults experiencing symptoms of depression, it's important to better understand the relationship between depression and memory problems," said co-author Dr. Adina Zeki Al Hazzouri, an assistant professor of Epidemiology at the University of Miami Miller School of Medicine.

The study titled "Greater depressive symptoms, cognition, and markers of brain aging" was published in Neurology, the medical journal of the American Academy of Neurology on May 9.

Assessment of participants

The researchers examined data from the Northern Manhattan Study, using 1,111 participants comprising of older adults who were mostly Caribbean Hispanic. The participants, who were at an average age of 71, had no history of stroke. Memory and thinking skills were tested at the start of the study and five years later. Additionally, the participants had psychological exams and provided brain scans.

22% of participants had greater depressive symptoms at the start of the study, based on the Center for Epidemiological Studies–Depression Scale, a test which measures the severity of depressive symptoms in a person.

Memory problems and smaller brain volumes

The study found that those with greater depressive symptoms also had worse episodic memory, which is the unique memory of specific events and personal experiences. This was after the researchers adjusted for variables such as age, race, anti-depressive medications, etc.

Findings also revealed differences in the brain of those with greater symptoms of depression. The authors noted smaller brain volumes and 55% higher risk for small vascular lesions in the brain after adjusting for sociodemographic, behavioral, and vascular risk factor variables.

"Small vascular lesions in the brain are markers of small vessel disease, a condition in which the walls in the small blood vessels are damaged," explained Dr. Al Hazzouri. "Our research suggests that depression and brain aging may occur simultaneously, and greater symptoms of depression may affect brain health through small vessel disease."

Exercise for relieving symptoms

Recent research also identified the type of exercise that is most effective in easing common symptoms of depression. The review was published in the journal JAMA Psychiatry on May 9.

Resistance exercise training (RET) may be "particularly effective for those with greater depressive symptoms" according to lead author Brett Gordon, a researcher from the University of Limerick in Ireland. RET typically includes weightlifting and strength training. After analyzing 33 clinical trials, Gordon and co-authors found that low mood, loss of interest in activities, feelings of worthlessness, and other symptoms of depression were reduced in participants regardless of age, gender, and health status.

These benefits are linked to the release of endorphins which can significantly improve mood and well-being. Experts also suggest that exercising can promote cell growth in the hippocampus of the brain.