Depression May Magnify APOE e4 Variant's Impact on Cognitive Decline, Study Finds

When an older person is not only depressed, but also has one or two copies of the APOE e4 gene variant, the risk of cognitive decline is even greater than if he or she had either depression or the variant alone. This is the finding from a large population study published in Psychosomatic Medicine, which was led by Kumar Rajan, Ph.D., an assistant professor at the Rush Institute for Healthy Aging at Rush University Medical Center. The study included 4,150 participants aged 65 or older from African-American or European backgrounds. About a third of the cohort had one or more copies of the APOE e4 variant.

"This finding has important implications for older adults, health care practitioners, scientists, and public-health experts—further demonstrating the complex interplay of mental health and genetic markers on late-life cognitive health," Rajan and his team concluded.

And in an accompanying editorial, Michelle Luciano, Ph.D., of the Center for Cognitive Aging and Cognitive Epidemiology at the University of Edinburgh, said: "Given that the APOE genotype is fixed in an individual, one of the questions that the research of Rajan et al. raises is the potential to curb cognitive decline through interventions targeting depression."

Information about the APOE e4 variant can be found in the Psychiatric News article "Disclosure of APOE Genotype Affects Memory Performance." To read more about depression in older individuals, see the Psychiatric News article "Resilience, No Depression Best Predict Successful Aging." For additional information on these topics, see Essentials of Geriatric Psychiatry, Second Edition, from American Psychiatric Publishing.

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