Sleep and mental health - a strong bidirectional relationship

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Sleep and mental health

We’ve all experienced how significantly sleep can impact our mental health and wellbeing. From the times we got little sleep and felt nervous and downbeat, all the way to those perfect nights of refreshing sleep when a smile couldn’t get off our face the next day. Sleep, not just anecdotally, plays an important role for mental health. And here I don’t only mean how you will feel the next few days, but rather how chronic poor sleep can lead to considerable mental health disorders. This relationship is bidirectional, and studies have shown that psychiatric condition such as depression or anxiety disorders can lead to insomnia, which can in turn worsen the underlying mental disorder.

So, how does poor sleep increase the risk of mental disorders? Depression is one of the most prevalent disorders out there, with more than 300 million people worldwide affected. Unfortunately, 3 in 4 people with depression also show symptoms of insomnia and excessive daytime sleepiness. Is insomnia a cause or consequence of depression? It is difficult to say, but many studies have shown that insomnia could actually precede depression . Depressed patients with sleep disturbance are likely to present more severe symptoms and difficulties in treatment. What’s more, insomnia is the most common residual symptom in depressed patients and is considered a key predictor of depression relapse . On the other hand, antidepressants can disturb sleep or worsen sleep problems, primarily because of their pharmacological action. Selective serotonin reuptake inhibitors (SSRIs), for example?fluoxetine (Prozac),?inhibit the reuptake of serotonin back into the neurons, making its levels in the synapse between the neurons higher. This is important since a delicate balance of neurotransmitters, including serotonin, significantly influences sleep. If that balance is disrupted, which may happen with SSRIs, sleep problems may occur.

Most mental health disorders increase the risk of poor nightly sleep.

Anxiety disorders, which affect 1 in 5 adults, have a strong connection with sleep disorders. As the name suggests, anxiety, fear and/or worry can increase stress and put the person in a state of hyperarousal which can easily lead to insomnia . In this group, post-traumatic stress disorder (PTSD) is especially associated with sleep problems, mostly because of nightmares and negative thoughts that patients with PTSD have. One study even suggested that as many as 90% of US veterans with war-related PTSD have insomnia symptoms.??

Bipolar disorder and schizophrenia are also strongly associated with sleep problems. Patients with bipolar disorder experience episodes of mania and depression where they behave and sleep differently. Manic periods are usually associated with less sleep, whereas depressive periods are accompanied by excessive sleep. People with schizophrenia may experience sleep problems because of the nature of the disorder, but poor sleep can be exacerbated by medications too. However, the neurobiology behind how exactly these two disorders affect sleep is still not fully understood.

Autism spectrum disorder consists of several neurodevelopmental conditions which affect communication and social interaction. They are usually diagnosed in childhood and these children often have insomnia, which can negatively affect their quality of live and increase behavioral problems too.?

Overall, studies have shown that there is a strong relationship between mental health and sleep quality, with most mental health disorders increasing the risk of poor nightly sleep and thus worse mental and physical health. There is evidence that this connection is bidirectional, meaning that sleep problems may increase the likelihood of a mental disorder, but more research is needed to fully determine this. In the meantime, it is important to recognize and treat a sleep disorder in any patient, especially someone with a mental disorder (e.g. using cognitive behavioral therapy and improving sleep hygiene) since poor sleep can not only worsen the patient’s general quality of life, but also exacerbate the mental disorder itself.

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About the author

Alen Juginovi??is a medical doctor and postdoctoral researcher in the Department of Neurobiology at Harvard Medical School in Boston, MA, USA studying the effect of poor sleep quality on health. He is also organizing international award-winning projects such as Nobel Laureate conferences, international congresses, concerts and other, as well as participating in many events as a speaker. Feel free to contact him via LinkedIn for any inquiries.