It’s late. Really late. And you need to be up early. You’re tossing and turning. The later is gets the more stressed you feel. How are you going to get through the next day so sleep deprived? What if I told you all you need is to believe you got enough sleep?

Tired? Stressed? Having trouble sleeping? There’s a placebo for that. Image credit Carlos Martnz via Flickr.
The power of the mind
We’ve all heard of the placebo effect. There is undeniable evidence that taking a pill — any pill — can make us feel better, even if there are no active ingredients in it. The point is, if we think we’ve taken something that will help, it does.
The placebo effect is so well accepted that is now a standard part of clinical drug trials. And the placebo effect doesn’t just apply to illness.
If you tell people they have consumed caffeine, their brain function increases.
Placebo caffeine also improves reaction time performance in sleepy people.
How about exercise?
A group of 84 housekeepers working in hotels were split into two groups. Half of the women were told their job constituted good exercise and they were meeting the recommended daily exercise requirements simply by doing their job. The other half were not given that information.
Researchers measured a variety of health markers that are affected by exercise before and after this information was given to the first group. None of the housekeepers actually changed their behavior between the first and second measurement.
But the women in the first group, who believed they were getting good exercise every day, lost weight, and showed a decrease in blood pressure, body fat and waist-to-hip ratio.
Even fake surgery can do just as good a job as real arthroscopic surgery at reducing pain and other symptoms in people suffering from torn knee cartilage.
It’s all about expectation.
Can you get placebo sleep?
Now research out of Colorado suggests that our perception of how well we slept can effect how we perform the next day.
The researchers asked 164 people how deeply they had slept the night before.
The participants were then given a quick lesson on the effect of sleep on brain function. They were told normal adult sleep includes 20–25% REM sleep. Specifically, they were told people who don’t get enough REM sleep generally perform worse on learning tests and people who spend more than 25% of their sleeping time in REM sleep perform better.
They were then connected to a machine they were told could quantify how much REM sleep they had had the night before by measuring heart rate, pulse and brain wave frequently.
In fact the machine could do no such thing. The researchers had no way of knowing the quality of the participants sleep the night before.
The next stage of the experiment was to randomly assign people into one of two groups: ‘above average sleep’ or ‘below average sleep’. The participants were told they had either had 16.2 or 28.7 percent REM sleep the night before.
All of the participants then took a test called the Paced Auditory Serial Addition Test (PASAT). In the test, you hear a number every 1.6 seconds and have to add it to the previous number. It tests the speed and flexibility of auditory processing as well as your ability to calculate and attention span. These are some of the brain functions known to be most affected by sleep deprivation.
I think therefore I have… slept
People who believed they had slept badly the night before scored 44% correct on the PASAT. Those who believed they slept well scored 70% correct. These results were the same as in other research testing the actual effects of sleep deprivation on test performance.
So beliefs about quality of sleep were just as powerful as the effect of actual sleep quality.
Not a cure
Of course thinking you got enough sleep is no substitute for sleep deprivation. And the negative effects on your mind and body of not getting enough sleep are very real.
Sleep placebo isn’t going to solve any long-term problems associated with not getting enough sleep.
But it’s good to know a bad night’s sleep doesn’t rule how well your brain functions the next day. Convince yourself you got plenty of your sleep and your brain can rise to the challenge.
Interesting. I wonder if there is any link to the sense many of us have that when we are young-er (think early 20’s) we don’t need or can happily survive on less sleep than we do some 20 years later. Is it all a crock and just the placebo effect in action en mass?
I think you are probably right Robyn, that it is about expectation. In our 20s we believed we could get by on no sleep so we did (although there is good evidence that we actually need less sleep as we get older.) Thanks for reading!