a of a verb or voice : showing that the subject of a sentence is the one doing the action expressed by the verb. âPickedâ in âI picked the applesâ is an active verb because it shows that the subject âIâ is the one who picked the apples.
Sleep deprivation is the condition of not having enough sleep; it can be either chronic or acute. A chronic sleep-restricted state can cause fatigue, daytime sleepiness, clumsiness and weight loss or weight gain. It adversely affects the brain and cognitive function. However, in a subset of cases sleep deprivation can, paradoxically, lead to increased energy and alertness and enhanced mood; it has even been used as a treatment for depression (see below). Few studies have compared the effects of acute total sleep deprivation and chronic partial sleep restriction.
Short-term effects of sleep deprivation can include irritability and a loss of motivation, and when these continue to manifest, they can contribute to mood disorders, including depression. And it works the other way, too: the onset of depression can lead to troubled sleep, including insomnia.