May is designated as the mental awareness and wellness month. As we end the month, it’s a good excuse to reflect upon the state of our mental health. Of the various aspects of mental wellness, the one I find most interesting is the effect of sleep on our mental well-being.

A good night’s sleep does wonders to the brain and the body. It enhances your memory, makes you more creative, makes you look more attractive, keeps you slim, and lowers food cravings. It protects you from cancer and dementia, wards off colds and the flu, reduces your risk of heart attacks and stroke, not to mention diabetes. It even makes you feel happier, less depressed, and less anxious.

Is there a more magical drug that can do all of this? Any of this?

Yet, somehow, one thing that is pretty common in the startup land - and I have been guilty of it myself - is to take pride in not sleeping enough. Those who pull all-nighters are considered gods amongst men. It’s scientifically proven that working crazy hours, sleeping late, waking up early, and doing so for prolonged periods is a sure-shot recipe for poor mental health. It often leads to stress, fatigue, and depression in the long run. As they say, the candle that burns twice as bright lasts half as long.

Why is sleep so important? I pull all-nighters often, and I am doing just fine.

Failed by the lack of education, most of us don’t realize the miraculous effects of an undisturbed sound 8-hour sleep. Various functions of the brain are restored during sleep and depend upon it. Of the many advantages of sleep, one of the most important ones is the impact on memory, both on acquiring new memories and retaining the old ones.

The functioning of a brain is quite similar to that of a computer. While we are awake, our brain constantly keeps acquiring new information. It keeps storing it in a temporary storage area within the brain, just like how an unsaved file on a computer is present in the in-memory RAM area. And just like the RAM in a computer has limited storage space, so does this part of our brain (called the hippocampus). Once the storage space is full, you risk losing (forgetting) the new information. Every night, while we sleep, the memories made during the day are transferred from the temporary storage to a more permanent storage area in the brain. It frees up space in the temporary storage area for the next day.

It means not sleeping entirely for even a day or not sleeping sufficiently (less than 8 hours) for prolonged periods can cause your temporary storage to be full. It impacts your ability to acquire new knowledge and make new memories. You would have noticed a dip in your ability to stay focussed and understand what is being discussed in a meeting if you haven’t slept well the night before.

The second benefit of sleep comes after learning new things, perhaps after your temporary storage is full. What happens the next night is even more fascinating. In our computer example, it’s the equivalent of clicking the save button on the document you have been working on; it transfers the information from the RAM to the hard disk.

Pressing this save button, i.e., going to sleep the next night, triggers memory consolidation in the brain. Not only are your memories transferred from the temporary storage (the hippocampus) to a more permanent storage area inside the brain (the cortex area), they are being processed too. Stale information gets updated, irrelevant facts get discarded, and sometimes even old lost and forgotten memories get salvaged. It’s the equivalent of a corrupted file on the computer hard disk getting restored. At some point or the other, you must all have had the “ah, yes. Now I remember” moment waking up after a good night’s sleep.

Finally, the brain clears up the temporary storage space to wake up the following day and be ready to make new memories and store them. The brain functions pretty similarly to a computer, but unlike the machine, it needs downtime every day to work efficiently.

Why is it necessary to sleep for 8 hours every night? Some people do just as well with 6 hours or less?

It turns out, getting less sleep consistently over a long stretch is equivalent to not sleeping at all.

David Dinges, a researcher at the University of Pennsylvania, did an experiment to find out exactly that - How much sleep can a person lose every night, and for how long, before their performance is objectively impaired? 

He devised a simple attention test. The participants need to look at the computer screen and press a button as soon as they see a blinking light on the computer screen; the light blinks periodically at a set interval. He measured the response and the reaction time of the participants. The participants in the study had to take this 10 mins test every day for fourteen days.

Dinges and his team studied a large number of subjects, who were divided into four groups. The first group was kept up for 72 hours straight, the second group was allowed 4 hours of sleep every night, the third group was allowed 6 hours of sleep, and the fourth group was allowed the full eight hours of sleep every night. Following were the findings of the experiment.

1. Although sleep deprivation of any kind caused slowness in response, it was not the biggest problem. There was something more telling: the participants would, for brief moments, stop responding altogether. It’s like they never saw the light blinking at all. Almost as if they completely dozed off for that small time window.
2. The first group, who was up 72 hours straight, saw the worst performance (not surprisingly). And their performance kept getting exponentially worse with every passing day.
3. With only 4 hours of sleep every night, the second group started seeing a steady dip in performance over time. By the 6th day, they performed as poorly as the first group did after the 1st night out. By the 11th day, their performance fell to the first group’s performance after their 2nd night out.
4. With 6 hours of sleep every night, the third group also started seeing a dip, although slightly better than the second group. Their performance after the 10th day was equivalent to the first group’s performance after their 1st night out.
5. However, the fourth group performed steadily throughout the 14-day study without any dip in performance. It was the group that received 8 hours per day of sleep.

It’s not known why exactly is 8 hours the magical number (it might be more for some). Enough empirical evidence suggests that for adults, a minimum of 8 hours of sleep every night is essential for the healthy functioning of the brain and the body. When you start getting more sleep consistently every night, you start getting healthier physically and stable emotionally.

The old saying that a good laugh and a long sleep are the best cures in a doctor’s book is right on the money. Sleep more. Stay healthy!

Best,
Kaddy

PS - If you want to read more about sleep and its benefits, I highly recommend this book - Why We Sleep by Walker, Matthew. It’s written in a way that will connect with everyone and is a fantastic read.

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Namaste