Sleep Deprivation

The latest research findings on the effects of sleep deprivation are more worrisome that what we had previously suspected. We are already aware that people who regularly sleep less than six hours per night can experience slow reaction times, loss of concentration, an increased incidence of obesity and other medical problems, and other sleep disorders.

A new study by Harvard Medical School researchers indicates that we are only fooling ourselves if we think that a lengthy “sleep-in” on the weekend of 10 hours or more will make up for late nights of shift work, television, texting, or video games. In the study “Uncovering Residual Effects of Chronic Sleep Loss on Human Performance,” published in the January 14, 2010 issue of Science Translational Journal, Harvard neurologist Daniel Cohen, M.D. showed that too little sleep over a long-term period of weeks causes a faster decline in performance than had been previously thought – up to 10 times worse.

The research, conducted at Brigham and Women’s Hospital in Boston, involved participants who lived at the hospital. They were allowed five days to catch up on sleep and then spent 21 days on a sleep cycle of about 33 hours awake and 10 hours asleep.

The results revealed that while short-term sleep deprivation leads to a decline in performance with each hour awake; this process can be rapidly overcome with an extended sleep episode, such as extra hours of sleeping in on a day off. On the other hand, with weeks of too little sleep, there is a faster decline in performance, particularly during what is known as the “biological late night” from 3-7 a.m. It is unknown yet how many nights of good sleep it would take to recover from this decline in performance.

In other words, staying up 24 hours straight takes a toll on functioning, but if you do that on top of getting less than six hours of sleep a night for three weeks, your reaction time and functional abilities may be up to 10 times worse than they would be if you had simply pulled an all-nighter. This research is especially significant for people who have jobs that require them to stay up for long hours – such as police officers, physicians, paramedics, truckers – as well as and students, who may not have the opportunity to regulate their sleep.

The research also showed that even though people who are chronically sleep-deprived may be almost near normal in performance when they awake, their ability to function deteriorates as their waking hours wear on. Chronic sleep loss leads to profound performance deficits that could result in catastrophic work errors, drowsy driving, or improper judgment in crucial situations.

With about 30 percent of Americans getting less than six hours of sleep per night, the implications of chronic sleep loss can be significant. Although it may be difficult for those who work odd hours, split shifts, or graveyard shifts to get a full night’s sleep, lifestyle changes can improve the quality and quantity of sleep.