Aim: Alzheimer's disease (AD) is characterized by cognitive symptoms and behavioral symptoms, and their association is inconsistent. The aim of this study was to investigate the relationship between cognitive function and the changes in behavioral and psychological symptoms of dementia (BPSD) in patients with AD.
Methods: A total of 101 patients with probable AD were enrolled (57 women and 44 men, mean age 77.6 ± 7.7 years). The Category Verbal Fluency Test (CVFT), the Mini-Mental State Examination (MMSE), the Constructional Praxis Test, the Delayed Word Recall Test, the Clinical Dementia Rating Scale, and the Neuropsychiatry Inventory (NPI) were administered at baseline. The NPI was reassessed with a median follow-up duration of 10 months (range 6–18 months). The change in the NPI scores was defined as the end-point score of the NPI minus the initial one. The associations between the changes in NPI total score, its four subdomains (hyperactivity, psychosis, affection, and apathy), and cognitive function were examined using multivariate linear models. The results were adjusted for confounders including demographics, baseline NPI, and duration of follow up.
Results: The mean MMSE was 18.6 ± 5.6, the CVFT score was 7.1 ± 3.9, and the NPI score was 10.9 ± 13.8. Regression analyses found that the CVFT score (β = −0.32, P = 0.004) was significantly associated with the change in NPI score, but not the MMSE, the Delayed Word Recall score, or the Constructional Praxis score. The CVFT score was significantly associated with changes in the psychosis subdomain (β = −0.34, P = 0.001), but not the other subdomains.
Conclusions: Our study showed that CVFT was predictive of the changes in behavior disturbance in patients with AD, particularly in the psychosis domain.