Memory disorders: novel treatments, clinical perspective.

The aging of the society is accompanied by a strong pressure to develop drugs to treat age-related memory disorders. This paper examines the discrepancy between the results of preclinical tests, which have identified a large number of putative cognition enhancers, and the limited clinical efficacy of most of them. The predictivity of the preclinical tests is discussed, and the criteria for evaluating the therapeutic efficacy of the cognition enhancers are examined. An analysis is made of the novel treatments presently available or under investigation. In light of the results of the trials with tacrine a warning is given not to expect striking clinical improvements by only attempting to restore signal transmission, disrupted by aging and dementia, without modifying the underlying morphological alterations.