Relations of neuropsychiatric symptoms with disease stage, sex, and daily function in mild cognitive impairment and dementia due to Alzheimer's disease: A cross-sectional study

Objective: To reveal the relations between neuropsychiatric symptoms (NPS), stages of cognitive impairment, sex, and daily function in patients with mild cognitive impairment (MCI) and dementia due to Alzheimer's disease (AD). Methods: A cross-sectional study was conducted from 2014 to 2021 on 1154 patients. Cognitive function, disease severity, NPS, and daily function were evaluated by Mini-mental State Examination, Clinical Dementia Rating Scale, Neuropsychiatric Inventory, and Activities of Daily Living (ADL) respectively. Multivariate logistic regression and linear regression were used to explore the correlations between NPS, disease stage, sex and ADL. Results: Affective disturbance displayed the highest prevalence from MCI (52.7%) to severe dementia due to AD (98.2%). Multivariate logistic regression revealed that aberrant motor behavior displayed higher prevalence between groups from MCI to severe dementia due to AD (OR = 4.710, P < 0.001; OR = 3.141, P < 0.001; OR = 2.722, P = 0.002, respectively). In patients with dementia due to AD, hallucination and depression were more prevalent in female (OR = 1.730, P = 0.001; OR = 2.376, P < 0.001, respectively) while male presented higher prevalence in apathy (OR = 0.608, P = 0.002). Linear regression analysis showed that delusion and sleep disturbance were significantly associated with basic ADL across all dementia due to AD stages (delusion: mild: beta = 0.113, P = 0.015; moderate: beta = 0.159, P = 0.019; severe: beta = 0.317, P = 0.018; sleep disturbance: mild: beta = 0.164, P < 0.001; moderate: beta = 0.167, P = 0.013; severe: beta = 0.308, P = 0.025) while anxiety was correlated with instrumental ADL from MCI to moderate dementia due to AD (MCI: beta = 0.119, P = 0.006; mild: beta = 0.149, P < 0.001; moderate: beta = 0.130, P = 0.042). Conclusion: Different subitems of NPS are strongly correlated with sex, stage of cognitive impairment, and ADL.