Problems Associated with Short Sleep: Bridging Laboratory and Epidemiological Studies

This review paper, (read it here) published in the journal Sleep Medicine Reviews, tells the story of what we know about short sleep and the negative health outcomes. The paper has 5 main sections: (1) an explanation of terminology that is often used to describe "short sleep," (2) an overview of laboratory-based studies of sleep deprivation, (3) an overview of population-based studies that looked at self-reported short sleep, (4) a review of the few studies that actually verify that those who report short sleep really do sleep short durations, and (5) some take-home points.

For the specific details and findings, you should read the paper. It outlines the current evidence, suggesting that short sleep may place individuals at increased risk for a number of negative health problems, including heart disease, diabetes, obesity, depression, poor performance, etc.

In addition to providing a summary of the current knowledge about short sleep, there are a few important messages that the paper brings to light:

1. Our terms are inconsistent and confusing. "Short sleep" has been used to describe everything from sleep for a few nights in a lab to habitual sleep at home, as well as sleep less than 8 hours, less than 5 hours, or any other amount. Also, reasons for short sleep (is this when you naturally sleep?) are largely ignored. For that reason, we, as a field, need to get our terms straight. Because lab studies do not generalize to the population, and population studies do not always describe effects that are reliable.

2. Short sleepers need to be better characterized. By lumping all people in a "short sleep" category together -- which we do no matter what our definition or cutoff is -- is automatically limited. This group could include lots of types of short sleepers, including those who are sleep deprived and those who are not. Also it includes people who choose to sleep less, and those who are forced to.

3. By talking about problems associated with short sleep, we assume that these problems could be fixed by simply sleeping more. Both the laboratory and population studies imply this in their language. But habitual short sleepers, who these studies are trying to generalize to, don't know if this is the case. First of all, do they even need more sleep? Second, CAN they sleep more? If so, how much more is needed? This has never actually been tested.

In general, the evidence suggests that not getting "enough sleep" -- which for most people is probably 7-8 hours, might be associated with a number of bad outcomes. However, research needs to explore these in more detail, including getting a better understanding of which short sleepers are sleep deprived and which are simply natural, "true" short sleepers.

Read the paper on this site: http://www.michaelgrandner.com/pages/research-publications.html.