BCHE and Alzheimer disease: The aim of the DOMINO-AD study is to determine, in a factorial (2 × 2) design, whether there is worthwhile benefit for patients, for whom there is uncertainty on whether or not to continue cholinesterase inhibitors, from: 1) adding memantine to donepezil, 2) switching to memantine or 3) continuing donepezil compared to 4) placebo.