Partial Myths About Sleep

We don’t know for sure these are myths, but the evidence to support them is sketchy or contradictory.

  1. Assertion: Prescription sleeping pills are stronger than over-the-counter pills

    Fact: Not necessarily.  The antihistamines in OTC sleep aids work for most people.  Prescription z-drugs work on a different neurochemical system, but they are not necessarily "stronger".  The effect of these drugs varies widely from person to person.  The prescription drug ramelteon, which works on yet another neurochemical system, is usually actually weaker, as reported by users.  Sometimes weaker is better, though, as it leaves the patient with less sleep inertia and disrupts sleep architecture less.

  2. Assertion: You know how long you sleep

    Fact: People notoriously underestimate how much they sleep, especially when they have several awakenings during the night.  If you sleep through the night and keep track of bedtime and rising time, you can probably get a handle on your sleep time (keeping a diary can help). Otherwise, a sleep monitoring device is the only way to really know how much time you spending sleeping.

  3. Assertion: You accrue a sleep debt during the work week and sleep extra on the weekends to repay that debt.

    Fact: Short-term sleep deficit is real and can be detrimental, but it is not clear how much "debt" builds up.  The extra sleep on weekends – sleeping during the morning, Hypnosor an afternoon nap – these may be driven partly by the body’s need to “catch up” on lost sleep.  They are also driven partly by opportunity and a time period with no work obligations that people take advantage of to have some fun.

  4. Assertion: There is a natural pattern of sleep for humans – about 8 hours during the dark.

    Fact: Humans are diurnal and naturally sleep at night and wake in the day. But there are many problems with the overgeneralization that everyone needs 8 hours of continuous sleep at night.  The amount of sleep needed every day varies from person to person, although about 6.5-9 hours is right for most.  Some people are night owls and tend to stay up late into the night and sleep into early morning daylight.  This practice is facilitated by, but not caused by, electronic media and entertainment.  Even before the electric light and the industrial revolution, there were night owls.

    Sleeping in one long stretch through the night is also only one way to do it.  Although attempts to go to a polyphasic sleep pattern usually fail (that pattern is too far from the human norm), a biphasic sleep pattern is common and many function well with a period of waking 1 to 2 hours during the middle of the night.

  5. Assertion: You need a good mattress to get a good night’s sleep/prevent back pain.

    Fact: We are not aware of any systematic study or test that has shown that to be true.  A comfortable sleeping spot is a part of good sleep hygiene, but there is no reason to think expensive mattresses are better than inexpensive ones.

  6. Assertion: Caffeine at night causes insomnia

    Fact: Caffeine is a stimulant and can keep people awake past the time they would have normally gone to sleep.  But like so many drugs, it has different behavioral effects on different people.  Stimulants like Ritalin are known for their paradoxical effect that cause some users to be able to sleep.  Many report caffeine helps them sleep better, although this may be an indication of addiction to caffeine.

  7. Assertion: Insomnia leads to weight gain because the person is so lethargic throughout the day he or she doesn’t burn as many calories.

    Fact: Insomnia can lead to increased body weight, but the mechanism for this is largely increases in appetite and changes in resting metabolic activity.  Lethargy due to daytime sleepiness may contribute, but it is not the dominant driver.

  8. Assertion: We need to sleep so we can dream. REM sleep is where we dream and the gold nugget of sleep.

    Fact: All stages of sleep are important. REM is the period with complex dreams and in many ways it is like waking - the EEG readings of brain waves look like those of waking. Reptiles and lower animals do not go through REM. It is a hallmark of higher animals. But scientists have repeatedly shown that stages 1, 2, and 3 are times when physiological processes needed for maintenance of the body and brain take place.

  9. Assertion: People who snore have apnea.

    Fact: Simple snoring (no apnea) is considered to be at the less serious side of the sleep-disordered breathing scale. It often progresses to apnea as the person gets older and/or heavier. Snoring has been found to be associated with the future onset of high blood pressure and diabetes. A quarter of American adults have metabolic syndrome – a catch-all term for a range of symptoms and there is a co-morbidity between sleep-disordered breathing and metabolic syndrome.

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