Drug Improvement of Cognition : Hope and Reality

Abstract

SummaryRecent research aimed at discovering and developing new drugs for diseases of cognition focuses heavily on Alzheimer’s disease and emphasizes mechanistic/biochemical approaches. Originally, research was based on a pragmatic search for compounds that would protect animals front disruptors of learning and memory. A series of compounds called nootropics do protect animals against these disruptions and offer hope that cognitive deficits may be amenable to pharmacological treatment. However, clinical development of these compounds is complicated by a number of factors. Among these is the poor correlation between animal models of cognitive loss and clinical disease states, a notable exception being the amnesic effects of benzodiazepines. Moreover, the inverted U-shaped dose-response function obtained in animal models and the lack of standard clinical outcome measures further complicate the development process. Tests that are beginning to gain acceptance as “standards” need to be characterized in terms of their validity, variability, and stability. There is a dearth of normative, especially longitudinal, data on cognitive decline. However, the great efforts being made in basic and applied research warrant cautious optimism.