One of the biggest changes in the structure of sleep (also known as ‘sleep architecture’) is seen in newborn infants. During the first year of life, infants transition from wake to sleep through REM sleep, as opposed to the NREM to REM progression seen in older ages [1]. Infants also begin to develop consolidated nocturnal sleep during their first year of life, with slow wave sleep (also known as ‘deep sleep’) occurring with the greatest frequency in young children and then decreasing with age [1]. Other age-related changes in sleep (sometimes beginning as early as young adulthood) include an increasing amount of time spent in the lighter stages (ie, N1 and N2) of sleep, more time spent awake, and an advancing of the circadian rhythm (ie, becoming sleepier earlier in the cycle) [1]. Figure 2.2 depicts changes occurring in sleep architecture across the lifespan [3].