Cognitive outcome measures.

Clinical trials of antidementia drugs must use a performance-based cognitive assessment as a primary outcome measure. There are well-established criteria for selecting or developing an optimal cognitive battery for Alzheimer disease (AD) trials that also apply to vascular dementia (VaD) trials. Because there is substantial overlap between the pattern of cognitive impairment in VaD and AD, the most efficient strategy for developing a VaD battery would be to begin with a well-established AD instrument and add subtests covering the additional domains that are more prominently impaired in VaD.