Evidence / Health

Am I Sleeping?

Graph taken from www.cdc.gov There are no darker hours than those spent trying to sleep but not sleeping, a condition known to millions of Americans as insomnia. Symptoms such as struggling to get to sleep, stay asleep, sleep soundly, and feel rested plague an increasing number of U.S. adults (an estimated 30% of us). According to a National Sleep Foundation survey, the consequences of insomnia are substantial: problems include “impaired concentration, impaired memory, decreased ability to accomplish daily tasks and decreased enjoyment of interpersonal relationships.”

Effect of short sleep duration (> 7 hours/night vs. < 7 hours/night) on ability to perform activities of daily living

Effect of short sleep duration (> 7 hours/night vs. < 7 hours/night) on ability to perform activities of daily living

As a chronic insomniac myself, I’m interested in any research relating to sleep or the lack of it, if nothing else because information makes me feel less alone in my struggles.  But this recent article  in the New York Times really intrigued me because it reviewed a recent publication suggesting that insomnia may be more about our perception of sleeplessness than a true lack of sleep.

The study, published in Journals of Gerontology: Medical Sciences, was conducted in over 700 older adults. They were asked questions about their sleep quality, such as how often they felt rested upon waking, had trouble falling asleep, had trouble waking up during the night, and woke up too early. Participants’ answers were compared to actual sleep characteristics estimated from three nights of actigraphy. Subjects wore an Actiwatch, which measures intensity and frequency of movement in 15 second intervals.  These movement data can then be used to calculate sleep characteristics related to falling asleep, staying asleep, waking up, and sleeping restlessly, in fragmented intervals.

Here’s what’s interesting. Similar to nationally representative surveys, about 30% of adults in the study reported problems waking up in the night, and another 12-13% had various issues with feeling rested, falling asleep, and waking up too early. And while these symptoms did correlate to quantitative sleep patterns, the effect was far less significant than you might imagine. For example, people who reported feeling well rested most of the time only got on average 4 minutes more sleep that adults who reported rarely feeling well rested. Similarly, subjects who reported falling asleep relatively easily fell asleep only 4 minutes faster than subjects who reported great difficulty falling asleep.  And, on average, the most restless sleepers actually got more sleep than adults who reported sleeping relatively soundly.

Certainly there are flaws with this study, one of the most important being that an Actiwatch accelerometer can only quantify sleep patterns but can’t distinguish between types of sleep (i.e., deep sleep, REM sleep, etc). And, periods of motionless may be captured as sleep by the acclerometer but may actually be periods of time when the wearer is just lying motionless and awake, pondering the dark and cold nighttime hours. Regardless, though, I have often wondered about my own recall of a sleepless night. When I’m paralyzed by the anxiety and frustration of sleeplessness, my recollection of how long I stayed awake may be exaggerated. It becomes difficult in the morning to remember what actually happened during a restless night, and I’ve wondered if I overestimate the impact of my insomnia on my sleep patterns.

I should note that authors of the study emphasize that insomnia has real health risks, and that it is a clinical condition. However, they conclude that sleep dissatisfaction – in other words, the psychological and emotional toll of disturbed sleep- may exceed the actual quantity of sleep lost to insomnia…yet another example of the power of the mind to influence our perceptions of reality.




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