Clinical characteristics according to depression screening tools in patients with Alzheimer's disease: view from self, caregiver-reported and drug-intervention pattern.

AIM: Depression in Alzheimer's disease (AD) has different clinical manifestations from primary depression of non-demented patients. We designed the present study to explore the following: (i) to determine the clinical characteristics of patients with and without depression according to observational and subjective depression screening scale; and (ii) to examine the depression prevalence rate in patients with AD according to these criteria.

METHODS

The Geriatric Depression Scale (GDS, observational scale) and Neuropsychiatry Inventory Depression subscale (NPI-D; subjective scale) were administered to 257 patients with drug-naïve probable AD. The study groups were classified into the three subgroups of "no-depression", GDS depression and NPI-DS (NPI-D significant) depression group, and the clinical characteristics of these subgroups were examined.

RESULTS

The NPI-DS depression group showed lower scores on the Korean version of the Mini-Mental State Examination compared with the no-depression group, and higher NPI subdomain scores compared with other groups. The GDS depression group showed higher NPI motor subdomain scores compared with the no-depression group. Depression defined by NPI-DS was the least frequent (10.5%), and NPI-DA (NPI-D any) was the most frequent (56.4%). The prevalence of depression defined by GDS and anti-depressant usage was 30.0% and 16.0% each. The level of agreement between the screening tools determined through the kappa index was from low to moderate.

CONCLUSIONS

The present study showed that different depression screening tools revealed a different prevalence and poor concordance rate among depression screening tools. Considering lower cognitive functions and higher BPSD symptoms in the NPI-DS depression group, NPI-DS could be associated with disease severity in AD patients. However, the clinical significance of GDS remains uncertain.