Are There Correlations Between Depression and Neuropsychiatric Symptoms at the Time of Alzheimer Disease Dementia Diagnosis?

Although uncommon at diagnosis, neuropsychiatric symptoms are exhibited by most individuals during the course of Alzheimer disease (AD) dementia. Depressive symptoms, however, are more common in those with AD dementia than neuropsychiatric symptoms. Using data from the National Alzheimer’s Coordinating Center (NACC), a team of researchers set out to determine correlations between neuropsychiatric and depressive symptoms at AD dementia diagnosis. Their findings were presented at the Alzheimer’s Association International Conference (AICC) 2024 in Philadelphia, PA.

“We sought to determine correlations between memory, executive functioning, language, neuropsychiatric symptoms, and depressive symptoms at AD dementia diagnosis, and to characterize neuropsychiatric and depressive symptoms across groups defined by substantial relative cognitive impairments,” the authors explained.

For their study, the authors derived composite Neuropsychiatric Inventory Questionnaire (NPI-Q) and Geriatric Depression Scale (excluding the memory question) scores using confirmatory factor analysis. Next, the authors defined a reference category of people with AD dementia whose neuropsychiatric symptom scores were similar to each other. These symptom scores included: memory, executive functioning, and language.

Additionally, other groups were “defined based on relative differences in cognitive domain scores,” the authors wrote. “We used multinomial logistic regression to test if neuropsychiatric and depressive symptoms differed across groups.”

Included in the study were 7747 people with AD dementia who went for a diagnosis visit. The researchers found that correlations between cognitive domains ranged from +0.30 to +0.50, correlations between cognitive domains ranged from -0.02 to +0.04 with NPI-Q composite scores, and -0.10 to +0.14 for the depressive symptom composite. Further, the correlation between depressive symptoms and the NPI-Q composite was +0.17.

The researchers did not find a difference in NPI-Q composite access groups, but scores for depressive symptoms differed across groups, “with higher scores in people with relatively greater executive functioning impairments and lower scores in people with relatively greater memory impairments, compared to people with similar domain scores,” the authors wrote.

The authors concluded that, “neuropsychiatric symptoms had trivial correlations with cognitive domain scores at AD dementia diagnosis, and did not differ across groups defined by substantial relative cognitive impairments,” the authors wrote. “Depressive symptoms were weakly correlated with cognitive domain scores, and differed across groups defined by substantial relative cognitive impairments. More research is warranted to further characterize depression and neuropsychiatric symptoms over the course of AD dementia.”

Reference:

Choi SE, Scollard P, S Mukherjee, et al. Neuropsychiatric symptoms and depression across cognitively-defined AD subgroups at the time of AD diagnosis: data from the National Alzheimer’s Coordinating Center (NACC). Talk presented at: Alzheimer’s Association International Conference 2024; July 28 – August 1, 2024; Philadelphia, PA. Accessed September 11, 2024. https://aaic.alz.org/