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Depressive symptom trajectories signify dementia risk more accurately than single assessments

Trajectories of depressive symptoms may inform dementia risk more accurately than individual single assessments of depressive symptoms, according to researchers.

“The relationship between depression and cognition in aging is complex, with evidence supporting different temporal associations between depressive symptoms and the onset of cognitive decline and dementia,” Allison R. Kaup, PhD, of Veterans Affairs Medical Center, San Francisco, and colleagues wrote. “Some studies suggest older adults may develop depressive symptoms in reaction to experiencing cognitive decline, other researchers identify depression as a risk factor for dementia, and others theorize that depressive symptoms and cognitive decline may both be symptoms of an underlying neurodegenerative process.”

To assess the association between depressive symptom trajectories and risk for dementia in older adults, researchers conducted a prospective cohort investigation of black and white community-dwelling older adults in the Health, Aging, and Body Composition study (n = 2,488). Trajectories of depressive symptoms were assessed from baseline to year 5. Incident dementia was determined by dementia medication use, hospital records or significant cognitive decline through year 11. Study participants had repeated depressive symptom assessments from baseline to year 5 with no dementia throughout that period.

Analysis indicated three depressive symptom trajectories: consistently minimal symptoms (62%), moderate and increasing symptoms (32.2%) and high and increasing symptoms (5.8%).

Having a high and increasing depressive symptom trajectory was associated with significantly increased risk for dementia (adjusted HR = 1.94; 95% CI, 1.3-2.9) whereas the moderate and increasing trajectory was not associated with risk for dementia after adjusting, compared with the consistently minimal trajectory.

The high and increasing trajectory was associated with dementia incidence, whereas depressive symptoms at individual time points were not, according to sensitivity analyses.

“Our results suggest that individuals’ trajectory of depressive symptoms may inform dementia risk above and beyond assessment of depressive symptoms at one time point alone. Because few participants in our study were taking antidepressant medication and no information about nonpharmacologic interventions was known, we were unable to thoroughly investigate the potential effect of treatment for depression on our findings,” the researchers concluded. – by Amanda Oldt

Disclosure: Kaup reports being given access to software programs and tablet devices by Akili Interactive Labs for use in research separate from and unrelated to the present study. Please see the full study for a list of all authors’ relevant financial disclosures.