Jesse Mindel is assistant professor in the Department of Neurology and a physician in The Ohio State University Wexner Medical Center.
What is sleep deprivation?
Sleep deprivation is usually defined as having inadequate total sleep time within a 24-hour day. Sleep deprivation is a common problem and can be due to many causes. These include increases in stress, making it more difficult to fall or stay asleep (usually transient) or a busy family, social or occupational schedule (such as is seen in night-shift workers) limiting a person’s sleep opportunity. Over time an individual accumulates what is called “sleep debt,” or the overall time subtracted from the body’s natural sleep requirement. Fortunately for those with chronic insufficient sleep, this sleep debt isn’t paid back with interest, and in fact recovery usually takes significantly less extra sleep than was lost. A more important point is that although there is significant variability in the amount of sleep required for daily functioning among individuals, the vast majority of people sleep around 7.5-8.5 hours if given an adequate opportunity.
What are the effects of sleep deprivation?
The effects of sleep deprivation are dependent on the amount of time subtracted from one’s normal sleep requirement on a day-to-day basis, as well as the cumulative effect of insufficient sleep over time. In other words, the severity of symptoms is directly related to the degree of sleep debt. Periods of mild sleep deficit (usually defined as less than two hours decrease per day) seem to be well tolerated. However, even brief periods of more severe sleep restriction have been proven to have adverse effects on memory, immune system function, mood and job performance, as well as an increased risk for automobile and workplace accidents (such as Chernobyl, Three-Mile Island, Exxon Valdez accidents). Longer-term periods of sleep restriction can have symptoms similar to medical conditions that result in pathological daytime sleepiness such as narcolepsy.
How can the effects of sleep deprivation be minimized?
Improvement in the daytime symptoms of sleep deprivation depends upon which effects are most bothersome. The daytime sleepiness most people notice can be improved with activity, light exposure and stimulants (such as caffeine). Unfortunately, excessive use of stimulants can have a negative effect on sleep as well as potential adverse medical effects. There is no treatment for the behavioral changes, mood changes and cognitive deficits that occur. The easiest way is to increase total sleep time on a daily basis. If this is not possible, then individual days with more prolonged periods of sleep can improve the symptoms of daytime sleepiness as well as cognitive performance by relieving a person’s overall sleep debt. In very deprived individuals, even short daytime naps can be helpful, but prolonged naps and frequent naps can also potentially have adverse effects.
Finally, if these things are corrected but daytime symptoms continue, those persons should be evaluated by a sleep professional to determine if there is an underlying cause for their daytime impairment that is unrelated to sleep opportunity. Depending on the cause, there may be non-medical or medical treatments to improve both nighttime sleep and daytime functioning.
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