Sleep deprivation causes stress, whether you're brilliant or dull-witted.
Sleep is the body's natural way of recovering from the stressors of life.
Adequate amounts of sleep increase the body's ability to handle stressful situations. Deprived of sleep, you can't bounce back from the everyday headaches and hassles of life. Fatigue and stress feed off of each other, creating a vicious circle. An inadequate amount of good-quality sleep is a major contributor to feeling emotionally out of control. Unfortunately, serotonin production dramatically decreases during times of stress.