[Dementia. Diagnostic problems]

NINCDS-ADRDA criteria are currently used to include patients into therapeutic trials in Alzheimer's disease (AD). However, specificity of these criteria is not very high (from 64 to 87% of diagnosis accuracy). The main causes of errors are the other degenerative dementias such as Frontal Lobe Dementias and Diffuse Lewy Body Disease. On the other hand, clinical heterogeneity of the patients fitting the criteria is large. To increase the power of therapeutic trials it is suggested: 1) to use specific criteria to rule out the other degenerative dementias when the efficacy of the tested drug is presumed to be specific for AD (cholinomimetics, inhibitors of beta-amyloid deposits...); 2) a better definition and assessment of the target symptoms when symptomatic improvement is the goal of the trial.