Concerning the prevalence of dementia.

A recent paper asserted that despite difficulties of measurement, the evidence suggests that the prevalence of dementia may be lower than is generally realized. However, this paper neglected the information provided by other recent studies which show relatively high values for the prevalence of dementia. On the basis of these latter studies and considering non-response, it is here suggested that, in fact, there is no good reason to suspect that the prevalence of dementia is lower than is generally believed.