Neuropsychiatric symptoms in Korean patients with Alzheimer's disease: Exploratory factor analysis and confirmatory factor analysis of the neuropsychiatric inventory

Background/Aims: We designed this study to examine subsyndromes in Korean patients with Alzheimer's disease (AD) using exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). Methods: Initial participants were 778 AD patients recruited from the Clinical Research Center for Dementia of South Korea and assessed via the Korean Neuropsychiatric Inventory. Those with ≥1 neuropsychiatric symptom were randomly divided into groups. Principal axis factoring with oblimin rotation was used to analyze group 1 inventory results, and maximum likelihood estimation extraction with Bollen-Stine bootstrapping was used for group 2. Results: The results of the EFA showed the presence of 4 subsyndromes: hyperactivity, affect, psychosis and apathy/vegetative symptom. The CFA results indicated this model was the best-fitting model for explaining these subsyndromes. Conclusion: Our model showed the best fit and identified 4 subsyndromes. This study might contribute to a clearer understanding of the neuropsychiatric symptoms in AD.