We were asked to consider differential diagnosis. We decided that it really is different from the other diagnostic modalities and cannot be treated in the same way as, for example, global or neuropsychological measures. In the context of this meeting, we believed it would be appropriate to consider clinical criteria. Thus, clinical criteria for the dementia syndrome as well as for specific diseases were discussed. We recognized that in the future, an increasing number of patients will present with cognitive impairment who do not fulfill the clinical criteria for dementia. These patients may alternatively have an isolated memory impairment syndrome. Nevertheless, a diagnosis will still need to be made in these patients, at least in terms of the underlying molecular pathology, in order to implement potential treatments.