Association between cognitive function, behavioral syndromes and two-year clinical outcome in Chinese subjects with late-onset Alzheimer's disease.

OBJECTIVE

To examine associations between behavioral and psychological symptoms of dementia (BPSD), cognitive function and clinical deterioration over 2 years.

METHODS

One hundred and four Chinese subjects with late-onset Alzheimer's Disease (AD) who presented to psychogeriatric clinics were followed for an average of 22.5 months. BPSD subgroups were categorized by latent class analysis using the Neuropsychiatric Inventory. Comprehensive cognitive profiles were performed with the Mattis Dementia Scale, the Hong Kong List Learning Test (HKLLT) and the Category Verbal Fluency Test. Interactions between cognitive function and behavioral syndromes were evaluated. Potential predictors for clinical deterioration were computed with logistic regression analysis.

RESULTS

Three latent classes of subjects with similar behavioral syndromes were identified: Low BPSD (44%), Affective (32%) and Psychosis (24%) groups. Association between cognitive functions and BPSD was not significant. At follow-up, a higher proportion of subjects in the Affective (70%) and Low BPSD (49%) groups remained stable at the same Clinical Dementia Rating. Baseline scores in the "recognition" test of the HKLLT and age were significant predictors for "deceased" status at 2-year follow-up.

CONCLUSION

The lack of association between behavioral syndromes and cognitive function suggests that these relatively independent dimensions of dementia should be examined individually for different prognostic significance.