Prediction of psychiatric response to donepezil in patients with mild to moderate Alzheimer's disease

Donepezil is a selective acetylcholinesterase inhibitor approved for the symptomatic treatment of mild to moderate Alzheimer's disease (AD). Since behavioral symptoms severely affect quality of life for AD patients and their caregivers, predicting behavioral responses to donepezil will be useful in managing patients with AD. In this study, we analyzed 70 consecutive cases with mild to moderate AD. Caregivers were interviewed with the Neuropsychiatric Inventory for behavioral assessment and 4-point improvement at week 12 was accepted as a treatment response. Twenty-one (30.0%) patients showed a behavioral response, while 42 (60.0%) showed no behavioral change and 7 (10.0%) worsened. Dysphoria, anxiety and apathy significantly improved after treatment among the responder group. The baseline profile including age, sex, Mini-Mental State Examination (MMSE), the Alzheimer's Disease Assessment Scale (ADAS-cog) and the Geriatric Depression Scale did not differ significantly among the three groups. Statistical Parametric Mapping analysis of single photon emission computed tomography (SPECT) images at baseline showed that cerebral blood flow in the premotor and parietotemporal cortices was significantly higher in the responder group than in the worse group. The present study suggested usefulness of SPECT imaging in the prediction of behavioral response to donepezil among AD patients even with similar psychiatric symptoms and cognitive functions.