Psychometric behaviour of BDI in Alzheimer's disease patients with depression

The psychometric properties of the Beck Depression Inventory (BDI) in subjects with Alzheimer's disease (AD) and depression have not been fully evaluated. Item endorsement patterns may be distorted by the presence of AD. This was tested by applying the BDI to a sample of 129 subjects with probable AD without depression and to 57 subjects with both probable AD and depression. It was found that the BDI under diagnoses depression in the context of AD. ROC curves for total BDI and cognitive and somatic items subsets showed low sensitivity and low areas under the curve indices. The results suggest that the BDI is not an ideal instrument to measure depression in AD. This may not result solely from the swing of the somatic items subset, but from other aspects which require further investigation.