Therapy Analysis - Sleep, A Mental Mystery
Exploring the nature of sleep and drugs designed for sleep disorders
While the boundaries of neuroscience are constantly being pushed back and new information about that most enigmatic of organs, the human brain, uncovered almost daily it seems, we still do not fully understand the fundamentals of one of the most common and routine actions to which we all are slaves - namely our need to sleep.
Sleep can be defined loosely as a natural and periodic state of rest during which consciousness of the external environment is suspended. Throughout the period of sleep there lie several stages, each lasting 90-110 minutes and usually referred to as light sleep, true sleep and deep sleep. Deep sleep further consists of two subdivisions known as rapid eye movement (REM) sleep and slow-wave sleep (SWS). Light sleep is, understandably, that transitional stage of sleep in which the consciousness is suspended between wakefulness and early onset sleepiness. Following this comes true sleep in which we lose both muscle tone (sleep paralysis) and complete consciousness of the external environment. The final stage is deep sleep: at this time our breathing and heart rates are at their lowest. The REM and SWS stage is when our brain is most active, often resulting in dreams; and is also the stage where some people experience common sleep disorders such as night terrors, sleep-walking and sleep-talking.
Sleep occurs in a continuous cycle of the above stages, alternating between non-REM and REM sleep. During non-REM, our bodies decrease our metabolic rate and increase the secretion of growth hormones, while during REM, increases in brain activity and eye muscle contractions are often observed.
