Sleep is a naturally recurring state of mind characterized by altered consciousness, relatively inhibited sensory activity, inhibition of nearly all voluntary muscles, and reduced interactions with surroundings. It is distinguished from wakefulnessby a decreased ability to react to stimuli, but is more easily reversed than the state of hibernation or of being comatose. Mammalian sleep occurs in repeating periods, in which the body alternates between two highly distinct modes known as non-REM and REM sleep. REM stands for "rapid eye movement" but involves many other aspects including virtual paralysis of the body.

 

The diverse purposes and mechanisms of sleep are the subject of substantial ongoing research. Sleep seems to assist animals with improvements in the body and mind. A well-known feature of sleep in humans is the dream, an experience typically recounted in narrative form, which resembles waking life while in progress, but which usually can later be distinguished as fantasy. Humans may suffer from a number of sleep disorders. These include dyssomnias (such as insomnia,hypersomnia, and sleep apnea), parasomnias (such as sleepwalking and REM behavior disorder), bruxism, and the circadian rhythm sleep disorders.

 

Teenagers need about 9 hours on average. Most adults need 7 to 8 hours a night for the best amount ofsleep, although some people may need as few as 5 hours or as many as 10 hours of sleep each day.

 

A new study (link is external) provides some important new information about how disrupted, insufficient sleep may contribute to the onset of emotional difficulties as well as the development of depression and other psychiatric problems. Researchers at the University of Pittsburgh School of Medicine investigated emotional responses in the brains of people with insomnia and found dysfunctional activity in an area of the brain that regulates and processes emotions. Their findings may provide an explanation for the mechanism by which disrupted sleep influences depression and other psychiatric conditions. 

 

All of us who’ve experienced insufficient, disrupted sleep know first-hand how being sleep deprived can negatively affect our emotional equilibrium. When we’re tired, we’re more likely to be short-tempered, impatient, and moody. Research such as this brings us closer to understanding the mechanics that may underlie a broad range of emotional disturbance and dysfunction.