Melatonin is a naturally occurring hormone that is released into the body when the eyes register that it's getting dark. When the eyes send the message to the brain that darkness is falling, a gland in the brain (the pineal gland) releases melatonin, which then signals the body to "wind down" and prepare for sleep. Melatonin regulates our waking and sleeping cycles in addition to performing other jobs. Consequently, insomnia is a symptom of a sleeping disorder characterised by persistent difficulty falling asleep or staying asleep despite the opportunity. Insomnia is a symptom, not a stand-alone diagnosis or a disease. By definition, insomnia is "difficulty initiating or maintaining sleep, or both" and it may be due to inadequate quality or quantity of sleep. It is typically followed by functional impairment while awake. This new and important book gathers the latest research from around the world in the study of melatonin and insomnia with a focus on such topics as: the neuropathology of insomnia in adults, hormones and insomnia, insomnia among suicidal adolescents, melatonin and nocturia, melatonin and its significance with anaesthesia and sedation, and others.