Clinical issues of cognitive enhancers in Alzheimer disease

Cognitive enhancers is a provocative and vague label for drugs used to treat dementia of the Alzheimer type. Several issues have to be carefully considered in order to perform reliable clinical trials with such compounds. The lack of an animal model appropriately matching the human pathology, the difficulty in finding worldwide criteria for clinical diagnosis and determining which patients are eligible and how they are best tested, methods of treatment, and interpreting results are undoubtedly the major problems to be solved. A review of the literature points out that the "day-after" approach of treatment (once severe neuropathological damage has been established) is no longer feasible, or has limited advantages. A different pharmacological approach, based on preventive measures during the first stages of the neurodegeneration, seems mandatory.