ABSTRACT
Among all the functions of the brain, sleep is possibly one of the most bizarre. After 16 hours or so of being awake, the brain appears to shut down and fall asleep for an average of about 8 hours. No other organ does this. It clearly serves a vital purpose, because sleep is inevitable; the brain itself will eventually overcome all attempts to stay awake and will induce a state of sleep. And sleep impinges heavily on health. Insufficient sleep is a major factor both in the cause and the symptoms of mental health and physical disorders. Sleep pattern disturbances are seen in several disorders, e.g. depression and anxiety states, and management of sleep disorders is an important component of treatment.
