By Rachel Davies, Nutritional Therapist

Sleep is one of the foundational pillars of wellbeing. When we don’t sleep well we expose ourselves to a myriad of different potential health struggles including mental health issues. As Professor of Neuroscience Matthew Walker explains in his book ‘Why We Sleep’:

  "There is no mental disorder in which sleep is normal…sleep loss and mental illness is best described as a two way street of interaction.”

In this blog we will look at the physiology behind how sleep and mental health are connected. Firstly it is important to understand that whilst we sleep, our body and mind are not inactive. In fact, sleep is a complex and ordered set of stages that performs vital functions to support our brain health. Think of it like a housekeeper, tidying up after the day: consolidating new information, processing memories and clearing out toxins. These activities are critical for mental sharpness, emotional stability, and long-term cognitive health. Sleep in essence nourishes our mental and emotional wellbeing. 

It is no wonder then that chronic sleep disruption is closely linked to poorer mental health. Research suggests that people with insomnia are 10 and 17 times more likely to experience clinically significant levels of depression and anxiety than those without insomnia. However, equally mental health disorders can impact the quality of your sleep. For example, it is estimated that up to 80% of individuals diagnosed with depression will experience insomnia or sleep disturbances. Sleep and mental health have a complex and bidirectional relationship often making it a vicious cycle. 

Let’s consider how poor sleep can impact on mental health, affecting mood, cognitive function, and emotional wellbeing:

Increased Anxiety and Stress

Sleep deprivation raises levels of the stress hormone cortisol. This heightened state of alertness can increase anxiety and make it harder to manage stress. Chronic poor sleep can therefore worsen anxiety disorders and lead to emotional volatility.

Depression

Poor sleep can disrupt neurotransmitter production and balance, leading to low mood and feelings of sadness. In particular poor sleep is associated with lower production of serotonin, the neurotransmitter that plays a vital role in mood regulation. REM sleep, the stage of sleep when we dream, is particularly important for processing emotions and mitigating the impact of negative experiences. When this stage of sleep is disrupted, it can lead  to a greater risk of depression or worsening of existing symptoms. Insomnia is both a symptom and a risk factor for developing depression.

Impaired Cognitive Function

Lack of sleep impacts the pre-frontal cortex, the part of the brain responsible for executive functions such as decision making and problem solving. It also slows down neurological pathways which reduce concentration and impacts memory consolidation, making it harder to retain new information, which can lead to irritability and decreased productivity. 

Emotional Instability and lower resilience to stress

In individuals who are sleep-deprived, the amygdala, the part of the brain responsible for processing emotion, becomes more sensitive to stressors, meaning that they may respond more intensely than those who are well-rested. Over time, this can lead to increased susceptibility to mental health issues.

Whilst neuroscientists are still exploring the exact mechanisms at play between sleep disturbances and poorer mental health, it is well established that chronic sleep deprivation is linked to a higher risk of developing conditions like anxiety, depression and bipolar disorder. 

Mental health is complex and often requires a multifaceted, holistic approach to achieve remission and resolution including diet, lifestyle, supplements, talking therapies, pharmaceutical interventions and more. However, prioritising quality sleep and implementing positive changes to your sleep routine should be top of your list. 

My top tips for supporting better sleep and mental health

1. Create a Sleep Routine: Going to bed and waking up at the same time each day helps regulate your body’s circadian rhythm, your natural sleep-wake cycle. Getting out in daylight within the first hour of waking really helps to cement these rhythms.
2. Limit Caffeine and Alcohol: Both substances can interfere with sleep cycles and lead to fragmented, poor-quality sleep. Additionally caffeine contributes to increased anxiety in many individuals whilst alcohol is known to have a depressive effect on the brain. 
3. Exercise Regularly: Physical activity is great for both mental health and sleep, so moving your body every day is key. However,  try to avoid vigorous exercise close to bedtime, as it can be too stimulating.
4. Practice Relaxation Techniques: Meditation, deep breathing exercises, and mindfulness can help reduce stress and promote relaxation, making it easier to fall asleep. Try this box breathing technique to get you started: Breathe in for 4 counts, hold for 4 counts, breathe out for 4 counts and hold for 4 counts. Visualise travelling around the 4 sides of a box as you do this. Just a few minutes can have a big difference on your mental state and relax you before bed.
5. Limit Screen Time: The blue light emitted by phones and computers can interfere with your body’s production of melatonin, the hormone that regulates sleep. Try to avoid screens for at least an hour before bedtime. This also helps to calm the mind before bed by avoiding consuming content that is too stimulating.
6. Try Extracted’s ‘Sleepee’ supplement: The ideal combination of top-quality ingredients, rigorously researched for their impact and efficacy in supporting better quality sleep. If you are taking any medication, always consult with your doctor or pharmacist before taking nutritional supplements. 

If you are struggling with your mental health, do speak with your GP who can help you in finding the right support. This article is for informational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.

www.racheldaviesnutrition.com

This blog is written by Nutritional Therapist Rachel Davies. Rachel is registered with the BANT (British Association of Nutrition and Lifestyle Medicine) and the CNHC (Complementary and Natural Healthcare Council). She continually attends CPD training to further her expertise and keep abreast of the fast moving field of nutritional science.