7.7 Myth: I’m Someone Who Only Needs a Few Hours of Sleep

The Committee on Sleep Medicine and Research from the Institute of Medicine agreed that the lowest sleep duration that supports optimal health in adults is seven hours per 24 hour period (Watson et al., 2015). Even partial sleep deprivation—missing just one or two hours—can contribute to decreased attention, concentration, memory, and critical thinking, and increased irritability, anxiety, and depression (Lund et al., 2010). Further, the effects of sleep deprivation are cumulative. In one study, participants who limited sleep to six hours per day for 14 days had similar performance deficits to participants who had no sleep for two nights. However, the six-hours participants were no longer able to recognize their own sleepiness or associated deficiencies after those two weeks (Van Dongen et al., 2003). In other words, cutting back on sleep for several days can have the same effects as pulling all-nighters and, over time, our awareness of the negative outcomes of sleep deprivation is diminished.

The shorter our sleep duration, the less REM sleep we get. REM sleep aids in assimilating new information with existing knowledge and enhances creative problem solving (Cai et al., 2009). During the first sleep cycle, the REM stage may only last a few minutes, but REM stages become longer as the individual’s sleep session progresses, for example in the early morning hours (Carskadon & Dement, 2005).