Aging, Sleep and Sleepiness Self-Assessment, and the Underlying Drives for Sleep and Wake

In 2016, a mini-issue of Current Aging Science (CAS) entitled "Effects of Aging on Circadian and Sleep Timing" has been published to report the state of the art in the studies of the effects of aging on the circadian and sleep regulating processes. The emphasis has been given to the regulatory processes involved in age-specific problems with sleep timing, continuity, and duration. Such problems can serve as targets for novel treatments for geriatric and sleep disorders. In the following 6 years, some new findings provided further insight into the previously recognized age-specific problems and highlighted new questions of research on the relation of aging to the regulatory mechanisms underlying circadian rhythmicity, sleep, and sleepiness. The theoretic framework of one of the directions of this research regards the interaction between the competing drives for sleep and wake as one of the basic features of regulatory processes underlying circadian rhythms, including such rhythms as the sleep-wake cycle and the diurnal variation in alertnesssleepiness levels. Here, earlier and more recently highlighted questions of the research in this framework were briefly reviewed.