There are four essential physiological ingredients to support good mental health. Nutrition, exercise, breathing and sleep. This blog is going to briefly look at sleep.
I've always been a fan of sleep! Ever since I can remember, I've always loved sleep. As if I needed any convincing, the Army certainly provided it early in my training during a food and sleep deprivation exercise. The details are hazy (not surprisingly!). It involved about four to five days of 0-30 mins sleep per night whilst carrying out tactical movement through the bush, carrying heavy loads and navigating cross country with time constraints in small teams of four or five people.
All the good, bad and ugly parts of your character and personality appear when you've been food and sleep-deprived and physically exhausted for days. Moodiness, irritability, and simple mathematical and cognitive processing errors, among others, all come out to play. In the right training/learning environment, these can be potent tools for growth. However, in the real world of everyday work and life, they can be turned against you by others and, most importantly, yourself.
When it's starved of two of its three most critical needs (energy, oxygen and sleep), the mind starts playing tricks on you.
The brain uses about 20 per cent of the body's total energy needs in a resting adult. If the body is not getting any food (i.e., energy), then the brain and the body have to dig into internal emergency supplies. Although research shows this is okay in small doses for intermittent fasting, prolonged deprivation of nutrients can only have negative consequences for both the body and brain.
It should be no surprise that the brain needs oxygen to survive. While the exact circumstance varies, serious and potentially irreversible brain damage can result from five to ten minutes without oxygen. A lack of oxygen can have other insidious consequences over the short and long term, which I'll explore in a future blog about sleep apnea.
We still need to learn more about sleep and why it's essential for us compared to what we do know. The scientific community all agree that sleep is necessary for life. However, they're still figuring out exactly how and why that's the case. Here's some of what we do know.
Whilst there appear to be many physiological benefits of sleep, such as repairing cell tissue, metabolic and thermal regulation, energy saving and energy restoring functions, to name a few, it's believed that many, if not all, of those could be equally achieved through a period of quiet wakefulness which would allow the brain's natural survival mechanisms to stay on guard.
However, the fact that we enter a period of unconsciousness during sleep where we are all but defenceless to external threats indicates that the main reason for sleep, in the way that humans experience it, is mainly to serve the brain, not the body. Two key areas where sleep is believed to serve the brain are processing memory and synaptic plasticity.
The proper creation, storage, and retrieval of memories is essential for survival and evolution. If we've just eaten something that made us sick, it would be good to remember what it looked like and where it was so that we don't make ourselves sick again. Likewise, with threats to our lives, let's avoid that place or protect ourselves better next time.
Synaptic plasticity is the brain's ability to create new pathways based on new activities. Research suggests that post-learning sleep is the prime time for these new neural pathways to be created, and thus, if we aren't achieving decent quality sleep, we jeopardise the brain's ability to properly create and store learning (i.e., memory).
Sound sleep is linked to the proper creation and storage of memories. Perhaps unsurprisingly, then, poor memory and poor sleep have close links to depression, too. Sleep is vital to resilience. Indeed, as an edition of The Harvard Mental Health Newsletter said, "Once viewed only as symptoms, sleep problems may contribute to psychiatric disorders". Individuals experiencing poor sleep are at a substantially higher risk of developing severe mental health conditions such as depression and anxiety compared to those with restful sleep patterns.
Poor sleep also leads to fatigue. Whilst some physical symptoms of fatigue, such as yawning, rubbing eyes, and lethargy, are noticeable, other symptoms like irritability, moodiness, and cognitive impairment are also significant issues that can cause social upset at best or accidents at worst. Cognitive impairment limits the fatigued brain's ability to see the full context of a given situation, resulting in excessive confidence or self-doubt. When mixed with irritability and moodiness, it doesn't bode well for rational and reasonable interactions with oneself or others. Put simply, a fatigued brain just doesn't think clearly.
A good night's sleep is essential for repairing cell tissue, synaptic plasticity, memory functioning, and preventing fatigue. You'll be repaid with clarity of thought the next day and the ability to build upon lessons learned, be they for pleasure or survival. With clarity of thought and building upon lessons learnt, you'll also be contributing to a self-fulfilling cycle of good sleep supporting good mental health and good mental health supporting good sleep.