Sections
Sleep Disorders: Introduction | Neurobiology of Circadian Rhythms and Sleep | Clinical Assessment of Sleep and Sleep Disorders | Insomnia Disorders | Sleep-Related Breathing Disorders | Hypersomnias of Central Origin | Circadian Rhythm Sleep Disorders | Parasomnias | Sleep-Related Movement Disorders: Restless Legs Syndrome
and Periodic Limb Movement Disorder | Conclusion | Key Points | Suggested Readings | Online Resources | References
Excerpt
Sleep and wakefulness are fundamental behavioral-neurobiological
states present in all animals, including human beings. Although
the function of sleep and sleep–wake rhythms has long been
debated, it is unlikely that such a fundamental process will ever
be equated with a single function. Theories of the function of sleep
focus on several possibilities: