Purpose of review: This review will concentrate on the consequences of sleep deprivation in adult humans. These findings form a paradigm that serves to demonstrate many of the critical functions of the sleep states.
Recent findings: The drive to obtain food, water, and sleep constitutes important vegetative appetites throughout the animal kingdom. Unlike nutrition and hydration, the reasons for sleep have largely remained speculative. When adult humans are nonspecifically sleep-deprived, systemic effects may include defects in cognition, vigilance, emotional stability, risk-taking, and, possibly, moral reasoning. Appetite (for foodstuffs) increases and glucose intolerance may ensue. Procedural, declarative, and emotional memory are affected. Widespread alterations of immune function and inflammatory regulators can be observed, and functional MRI reveals profound changes in regional cerebral activity related to attention and memory. Selective deprivation of rapid eye movement (REM) sleep, on the contrary, appears to be more activating and to have lesser effects on immunity and inflammation.
Summary: The findings support a critical need for sleep due to the widespread effects on the adult human that result from nonselective sleep deprivation. The effects of selective REM deprivation appear to be different and possibly less profound, and the functions of this sleep state remain enigmatic.
aDivision of Pulmonary, Critical Care, and Sleep Medicine, Department of Internal Medicine, University of New Mexico School of Medicine
bProgram in Sleep Medicine, University of New Mexico Health Sciences Center, New Mexico, USA
Correspondence to Lee K. Brown, MD, Professor of Internal Medicine and Pediatrics, and Vice Chair, Clinical Operations, Department of Internal Medicine, University of New Mexico, School of Medicine, 1101 Medical Arts Avenue NE, Building #2, Albuquerque, NM 87102, USA. Tel: +1 505 272 6110; fax: +1 505 272 6112; e-mail: firstname.lastname@example.org