Depression, Genetic Variant Exacerbates Cognitive Decline in Elderly
Elderly patients who were diagnosed with major depression and who carried the APOE-e4 allele had greater cognitive decline.
WASHINGTON — Elderly patients who have been diagnosed with major depressive disorder (MDD) and who carry a genetic variant known to be associated with Alzheimer's disease experience greater cognitive decline than peers who do not have the mood disorder or the variant, according to new data presented at the Alzheimer's Association International Conference 2015.
Nunzio Pomara, MD, of NYU Langone's Pearl Barlow Center for Memory Evaluation and Treatment in New York City, and colleagues examined 91 subjects that were part of a three-year-long National Institutes of Health study investigating the connection between MDD and amyloid beta protein disturbances. Forty-five patients had an MDD diagnosis. All subjects had no evidence of dementia.
The researchers also wanted to see if the APOE-e4 allele, a known genetic risk factor for Alzheimer's, as well as cerebrospinal fluid (CSF) levels of amyloid beta 42, influenced cognitive decline. Earlier research by Pomara and colleagues found that elderly patients with MDD who are cognitively normal tend to have lower CSF levels of amyloid beta 42 compared with controls, “suggesting elevated levels of brain amyloid deposition despite no apparent memory loss or cognitive impairment,” according to their new poster.
Senior patients with depression who also carried the APOE-e4 variant showed greater decline on the Boston Naming Task (P<0.01). In addition, higher CSF total tau/amyloid beta 42 ratio was associated with a decline in memory among depressed subjects, regardless of APOE status, but not in controls.
“Our results indicate that cognitively intact depressive e4 carriers have greater decline in selective cognitive tests especially in a confrontation naming task even during a relatively short three-year longitudinal period compared to controls,” the researchers concluded.
- Pomara N et al. Poster #P1-110. "Predictors of Cognitive Decline in Elderly Depressives." Presented at: AAIC 2015; July 18-23, 2015; Washington, D.C.