Study finds no link between late-life depression, global amyloid deposition

Key takeaways:

• Antidepressants were linked to increased global amyloid in those with normal cognition, not mild cognitive impairment.
• More research may be needed due to the low number of patients with late-life depression.

ORLANDO, Fla. — Among a cohort of patients within the Atherosclerosis Risk in Communities study, no link was found between late-life depression and global amyloid deposition, according to a poster at the American Neurological Association.

“My grandfather was diagnosed with Alzheimer’s disease, and I grew up exposed to the condition,” Sylee Kanetkar, BS, Intramural Research Training Award Fellow at the National Institute of Neurological Disorders and Stroke, told Healio about her motivation for the research. “I was also interested in learning about depression, since many members of my family had gone through [it].”

Prior research has established that a history of depression as well as late-life depression are associated with an increased risk for developing AD and dementia; however, the mechanism behind this is not well understood, Kanetkar and colleagues wrote.

The researchers investigated associations between individuals diagnosed with late-life depression and deposition of amyloid in those without AD and related dementia.

Their analysis included 334 patients in the Atherosclerosis Risk in Communities (ARIC) study, a multisite, longitudinal cohort study that examined long-term risk factors for heart disease, stroke and associations with cognitive health. Enrollees were visited up to five times from the study’s inception between 1987 to 1989 and 2011 to 2013.

The researchers culled data from the second ARIC visit, chiefly self-reported depression symptoms in midlife via the Maastricht questionnaire, and the fifth ARIC visit, during which enrollees underwent the Center of Epidemiological Studies Depression assessment as well as 18-Florbetapir PET scans.

A total of 313 patients were subsequently listed as “not depressed” (median age, 75.7 years; 57.2% women), while 21 others (median age, 78.1 years; 57.1% women) were diagnosed with depression.

According to the results, neither persistent depressive symptoms from midlife nor depression in late life were associated with global amyloid deposition. This finding remained after utilizing multivariate logistic regression and adjusting for race, sex and cognitive status.

Data further showed that the use of antidepressants was associated with increased global amyloid in those with normal cognition but not in those with mild cognitive impairment.

“We found late-life depression was associated with increased amyloid in the amygdala, which is a region of the brain that is associated with emotional processing,” Kanetkar added.

However, the researchers noted that there was a low number of patients with late-life depression, limiting their findings.