The circular relationship between sleep and mental health

Written by: Pierre-Olivier Gaudreault, PhD. Psychologist specialized in sleep medicine at HALEO Clinic.

Published on: June 14, 2024 | Reading time: 🕐 3m

Everybody has experienced the physical and psychological effects of a poor night’s sleep. Beyond the daytime sleepiness it creates, bad nights can affect our mood but also increase irritability and frustration as well as lower our tolerance to stress. Unfortunately, our mental health can also affect the quantity and quality of our sleep. A good example is when we experience anxiety which can cause our level of arousal to increase at night and, in turn, lead to difficulty falling asleep. To make matters worse, when we don’t sleep well for a few nights, we tend to worry about our inability to get good sleep quality, which can become a self-fulfilling prophecy. 


How do we categorize our sleep loss? 

It is very important to clarify the many ways in which our time asleep can be impacted. We all know about those famous all-nighters when we stayed awake through the night. But did you know that partial sleep restriction (i.e., sleeping less than our average 8h of sleep) and even sleep fragmentation (i.e., repeated awakenings during the night) can also have a negative impact on our functioning? There is definitely a dose effect when it comes to sleep loss, but we know for instance that repeated periods of short sleep restriction still affect how our brain processes positive emotions and increase anxiety symptoms.1 


Insomnia and mental health disorders 

Consistent with this specific sleep and mental health relationship, researchers have identified significant overlap between sleep disorders such as insomnia and other psychological disorders. Insomnia—characterized by difficulty falling asleep, maintaining sleep, or waking up too early with an inability to fall back asleep—is commonly experienced by individuals suffering from depression, bipolar disorder, anxiety disorders, substance abuse, eating disorders, and schizophrenia. Indeed, epidemiological studies showed that individuals with prior history of insomnia were twice (2x) more likely to develop anxiety disorders, four times (4x) more likely to develop a major depressive episode, and even seven times (7x) more likely to develop drug abuse or dependance.2 


What comes first, sleep or psychological disorders? 

For the moment, it is safe to say that there is a bidirectional relationship between these disorders meaning that symptoms of sleep and mental health disorders are reinforcing the other. In the case of insomnia and depression for instance, sleep problems can lead to fatigue, irritability, decreased positive emotions, and cognitive problems which can heighten the level of depression. On the other hand, depression is known to cause sleep disturbances, such as early morning awakenings, sleep fragmentation, and even alterations of the circadian processes that regulate sleep. For some individuals, these sleep disturbances may become entrenched over time, progressing to full-blown insomnia.  

Improving sleep leads to better mental health 

The good news is that taking actions and treating insomnia often has a positive effect on the overall mental health. Recent scientific reviews found that improving sleep quality, mainly using Cognitive-behavioural therapy for insomnia (CBT-i, the recommended first-line treatment for insomnia), led to better mental health including improved depression and anxiety symptoms.3  

At HALEO, our CBT-i program is not only focusing on behavioural strategies to optimize the biological processes that regulate sleep, but it also teaches ways to manage intrusive thoughts that interfere with falling asleep as well as methods to relax the body and mind in preparation for sleep.  

After participating in our CBT-I program at HALEO, 9 out of 10 clients no longer show clinical insomnia symptoms, and 85% have significant improvement in their symptoms of anxiety and/or depression. 


Need help with your sleep? 

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  1. Palmer CA, Bower JL, Cho KW, Clementi MA, Lau S, Oosterhoff B, Alfano CA. Sleep loss and emotion: A systematic review and meta-analysis of over 50 years of experimental research. Psychol Bull. 2024 Apr;150(4):440-463. doi: 10.1037/bul0000410. Epub 2023 Dec 21. PMID: 38127505.
  2. Riemann D. Insomnia and comorbid psychiatric disorders. Sleep Med. 2007 Dec;8 Suppl 4:S15-20. doi: 10.1016/S1389-9457(08)70004-2. PMID: 18346672.
  3. Scott AJ, Webb TL, Martyn-St James M, Rowse G, Weich S. Improving sleep quality leads to better mental health: A meta-analysis of randomised controlled trials. Sleep Med Rev. 2021 Dec;60:101556. doi: 10.1016/j.smrv.2021.101556. Epub 2021 Sep 23. PMID: 34607184; PMCID: PMC8651630. 
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