Why Is Sleep Important? The Connection Between Sleep and Mental Wellbeing

Mental Health

Woman feeling refreshed drinking tea after a good nights sleep.

We’re always being told how important sleep is. Research now shows just how important good sleep is for our mental health and overall wellbeing.

Sleep requirements change with age, but we all need a good quality and quantity of sleep. This is achieved by developing good ‘sleep hygiene’, the habits and routines around sleep.

So why is sleep important? There are many theories, but the most important things that happen during sleep are:

  • The body releases hormones for healing, repair and growth
  • The immune system regenerates and produces essential proteins
  • It seems likely that sleep renews or restores brain energy, but exactly how this happens is unclear
  • The brain’s connectivity and plasticity is improved, affecting learning and memory

What Happens if We Don’t Get Enough Sleep?

We are all familiar with the short term symptoms of poor quality sleep like:

  • Feeling drowsy
  • Being moody and irritable
  • Memory problems and struggling to make decisions

The long term effects are more serious. Without a good night’s rest, the body doesn’t have time to repair cells and give the body’s immune system a boost. When a person isn’t sleeping well, they become run down and prone to infections and illness. Long-term sleep problems are linked to high blood pressure, obesity, heart disease, diabetes and stroke.

The central nervous system is most impacted by poor sleep and there are also short and long-term mental health problems.

The Mental Health Effects of Poor Quality Sleep

Research by the Sleep Health Foundation found adolescents who don’t get enough sleep find it hard to regulate their emotions. This was less noticeable in adults but, for all age groups, there is a link between less sleep and depression. By not getting enough sleep, people increase their risk of depressed mood.

The evidence suggests that poor sleep and depression may be a vicious cycle. Once someone has poor mental health, they are more likely to suffer from poor sleep which further impacts their mental wellbeing.  

The Journal of Neuroscience published a study in 2014 that revealed 24 hours of sleep deprivation in healthy people can cause hallucinations and schizophrenia-like symptoms.

One night of lost sleep increases beta-amyloid levels, a protein in the brain linked to impaired brain function and Alzheimer’s disease. In people with Alzheimer’s, the beta-amyloids clump together to form plaques, which hinder neuron communication.

What happens in the brain during sleep?

Different bodily and brain functions happen each night during the different cycles of REM and NREM sleep.

During sleep, the brain stores and consolidates its memories. Learning and memory can be affected if a child doesn’t get enough sleep. For adults, not getting enough shut eye can cause poor work performance and accidents such as car crashes.  

The Brain “Cleans” Itself

Scientists have discovered that while we sleep the brain is busy cleaning itself.  In the journal Science, an article on sleep named this cleaning process as the ‘glymphatic system’. Brain cells shrink by 60% in size to help flushing out the toxins responsible for Alzheimer’s disease and other neurological disorders. Almost all neurodegenerative diseases are linked to accumulating cell waste products.

The brain doesn’t use the lymphatic system like the rest of the body, it relies on its own complex system of molecular gateways to clear waste products. This cleaning process can’t occur while a person is awake because the brain is too busy performing other functions.   

What Causes Poor Sleep?

The leading causes of poor quality sleep are lifestyle factors and bad habits. Using phones and laptops in the hour before bed and caffeine consumption are the two major factors that cause sleep problems. Both are responsible for shorter sleep times and more daytime tiredness.

Adolescents benefit from parent-set bedtimes and other sleep hygiene strategies such as listening to classical music, relaxation techniques, and phone restrictions can all help with getting to sleep faster and staying asleep longer. Taking sleep medications can cause long-term difficulties getting to sleep for older adults.  

Nutrition and sleep are also linked. Spicy and acidic foods can cause heartburn and lying down makes it worse. If you want to use diet to improve your quality of sleep, drinking milk before bed can help. Milk contains tryptophan which the body uses to make serotonin. Natural remedies such as melatonin or valerian may also help improve sleep although the research on melatonin is inconclusive.

How Much Sleep do You Need to Be Healthy?

The amount of sleep you need varies depending on your age and your own unique requirements. General guidelines for health sleep by age are:

  • Babies (under 12 months):  12 to 16 hours
  • Children (under 5 years):     10 to 14 hours
  • Children (6 - 13 years):         9 to 11 hours
  • Teenagers:                                 8 to 10 hours
  • Adults (18 - 65 years):          7 to 9 hours
  • Adults (over 65 years):         7 to 8 hours

Take Sleep Seriously For Your Health

Next time you think it’s fine to stay up and watch another episode on Netflix or stay out an extra hour at night, think of the reasons your body and brain need sleep. Putting yourself at risk of mental health problems associated with poor sleep habits isn’t worth it. Get an adequate amount of sleep and your brain will thank you for it.

If your sleep is impacted by stress or anxiety, contact a qualified therapist at PeopleSense by Altius on 1300 307 912 or (08) 9388 9000, or contact us online.

Category: Mental Health