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  • Kevin Humphreys

Good sleep is important for good Mental Health


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!) but 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 plus physically exhausted for days on end. Moodiness, irritability, simple mathematical and cognitive processing errors among others all come out to play. In the right training/learning environment, these can be incredibly powerful tools for growth. However, in the real world of everyday work and life, they can be turned against you by others and importantly, yourself.


The mind starts playing tricks on you when it’s being starved of two of its three most critical needs (energy, oxygen and sleep).


In a resting adult, the brain uses about 20 per cent of the body’s total energy needs. If the body is not getting any food (ie: energy), then the brain and the body are having to dig into internal emergency supplies. Although research is showing this is not a bad thing in small doses such as intermittent fasting, prolonged deprivation of nutrients can only have negative consequences for both body and brain.


With regards to oxygen, it should be no surprise that the brain needs oxygen to survive. Whilst it varies depending on the exact circumstance, serious and potentially irreversible brain damage can result from five to ten minutes without oxygen. There are other insidious consequences from a lack of oxygen over the short and long term too which I’ll explore in a future blog about sleep apnoea.


Why sleep is so important


As for sleep and why it’s important for us, there is more that we don’t yet know compared to what we do know. The scientific community all agree that sleep is essential for life, but they’re still working 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, storing 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 didn’t make ourselves sick again. So too with threats to our life; let's avoid that or protect ourselves better next time...


Synaptic plasticity is the ability of the brain 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 the learning (Ie, memory).


Just as good sleep is linked to proper creation and storage of memories, 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 actually contribute to psychiatric disorders”. People who sleep poorly are much more likely to develop significant mental illnesses, including depression and anxiety than those who sleep well.


Poor sleep also leads to fatigue


Whilst there are many physical symptoms of fatigue such as yawning, rubbing eyes and lethargy, irritability, moodiness and cognitive impairment are significant issues as well. 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.


Whether it’s for repairing cell tissue, synaptic plasticity, memory functioning or preventing fatigue, a good night's sleep is essential. You’ll be repaid with clarity of thought the next day and the ability to build upon lessons learnt, 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.