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. Geriatr Gerontol Int 2014; 14: 660–666.