Sleep and cognitive (memory) function: research and clinical perspectives.

The field of memory and sleep is controversial and extremely interesting, and the relationships between thought processes, i.e. cognition and sleep, have recently been examined in a variety of clinical and basic research settings, as well as being the object of intense interest by the general public. For example, there are data which demonstrate that insomnia, as well as specific sleep disorders, can have a negative impact on sleep cognition as well as affect daytime patterns of cognitive functioning. Thus, sleep, disturbed sleep and the lack of sleep appear to affect cognitive and memory functions. An International Workshop dealing with Sleep and Cognitive Function: Research and Clinical Perspectives was convened in Cancún, Mexico, 1-4 March 1999 under the auspices of the World Health Organization Worldwide Project on Sleep and Health and the World Federation of Sleep Research Societies. A great number of areas of intersection between sleep and cognitive function were examined during the course of the Workshop, such as aging, cognition and sleep and the dream process and sleep. The results of these discussions are included in a WHO publication (WHO Doc.: MSD/MBD/00.8). In the present report we concentrate on presenting a summary of a coherent set of data which examine memory consolidation during sleep and the impact of insomnia on cognitive functions. Based upon these data, a review of memory and drug effects that are sleep-related, and an examination of the relationship between hypnotics and cognitive function are included. Finally, a summary of recommendations of the Workshop participants is presented.