Sleep is a highly underrated activity. Sleep is the primal form of introversion, a state in which we temporarily but regularly withdraw almost totally from the external world. (See my previous post on introversion and extraversion.) Living as we do in such an extraverted society, most suffer from a chronic insufficiency of sleep. Some studies indicate that people today are sleeping less than they did several decade ago, and that sleep deprivation is a possible risk factor for serious physical conditions including heart disease, atherosclerosis, obesity, insulin resistance, diabetes, and suppression of the immune system. In addition, sleep deprivation and resulting sleepiness play a part in traffic accidents and other mishaps involving human error.

Moreover, lack of sleep can lead to a transitory mental state known as abaissement du niveau mental: a temporary reduction of consciousness, in which ego defenses are weakened, rendering us more susceptible to the unconscious. Sleep deprivation induces this state, sometimes causing or exacerbating symptoms such as anxiety, depression, mania, paranoia, irritability, anger and rage. Hence the value, even for hardcore extraverts, of getting enough of the compensatory, restorative introversion sleep provides--especially during times of intense stress. While each person differs in the amount of sleep needed for replenishment, eight hours being about average, it is crucial to get sufficient amounts and adequate quality of sleep, and to do so on a regular schedule. Sleep heals the body, clears the mind, and restores the soul. Recent studies indicate that getting at least 7-8 hours of sleep nightly leads to losing excess pounds. In patients suffering from insomnia or hypersomnia--sometimes secondary symptoms of anxiety and depression-- regulating sleep pharmacologically or otherwise can be  crucial to successful psychotherapy.