This article is the next in The Conversation’s six-part series on insomnia, which charts the rise of insomnia during the industrialization of sleep apps today. Read other articles in the series here.
The 2004 movie The engineer gives us a striking depiction, albeit a fictional one, of the psychological effects of chronic insomnia.
When people don’t get enough sleep, theirs Memory and concentration are impaired in the short term. They are also less able to regulate their emotions.
If sleep difficulties continue, long-term psychological effects may include anxiety, depression, mania and psychosis. Indeed, Christian Bale’s character in The Machinist has increasingly vivid visual hallucinations and paranoid delusions as his insomnia deepens.
The relationship between insomnia and mental disorders is complex. It’s not just a case of “which comes first, the insomnia or the mental disorder?” Insomnia and mental disorders are interconnected in ways that we do not yet fully understand.
Read more: A brief history of insomnia and how we fell asleep
What is insomnia? Is it a mental disorder?
Insomnia is by far the most common sleep disorder. Estimated 12-15% of Australian adults at any time meet the criteria for insomnia.
People with insomnia have frequent and persistent difficulties falling asleep and staying asleep and/or falling back asleep after early awakening. Insomnia not only affects the quality of people’s sleep, but also how they function the next day.
Many of the factors that trigger insomnia and help maintain its negative long-term effects are psychological or behavioral. These include:
psychosocial stressors (such as money, work or family problems)
attention bias and worry about sleep (the more we think and worry about sleep, the worse it gets)
poor sleep habits (such as irregular sleep and wake times);
Insomnia is not a mental disorder in the same way that, say, depression and anxiety are mental disorders. Insomnia is recognized sleep disorder which nevertheless has close links with a wide variety of mental disorders.
Also Read: What Is Insomnia Like For Most People Who Can’t Sleep? You’d never know it from the movies
Many people have both insomnia and a mental disorder
About halfway through of all people diagnosed with insomnia also have an associated mental disorder. The most common ones associated with insomnia are depression, anxiety, bipolar disorder, post-traumatic stress disorder, and substance-related disorders.
We don’t (yet) know why we see such high levels of mental disorders in people with insomnia. But there are several basic theories, such as:
one common genetic risk for insomnia and mental disorder. In other words, some people’s genes may predispose them to both conditions
one common neurobiological answer. How the brain responds to sleep loss may be linked to how systems in the brain control cognition, emotion and reward. Disturbances of these brain functions are implicated in a number of mental disorders
inflammation and/or immune system dysfunction may underlie both insomnia and mental disorders.
Read more: How dangerous is insomnia? How fear of what it does to your body can ruin your sleep
Which comes first?
It further complicates the picture it is evidence insomnia may occur before one develops a mental disorder or afterward. The researchers call this a “two-way” relationship.
We cannot say that one causes the other. We can only say that there is a clear relationship between them.
This link means diagnosis and treatment of one may have implications for diagnosis and treatment of the other. For example, if you don’t adequately treat insomnia, it can worsen the symptoms of someone’s mental disorder, increasing both severity and risk of recurrence.
A type of talk therapy known as cognitive behavioral therapy for insomnia (CBTi) aims to change the unhelpful thoughts, feelings, emotions and behaviors that contribute to insomnia. And, in many cases, successful treatment of insomnia with CBTi it can also heal one’s mental disorder (and vice versa).
CBTi is special effective in the treatment of insomnia and depression, substance use or post-traumatic stress disorder. But it is less effective in treating insomnia and psychosis or bipolar disorder.
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Filling in the gaps
There is much we do not know about the relationship between insomnia and mental disorders. Last year an international panel of experts that are described the research needed to fill knowledge gaps. Recommendations included:
long-term studies starting in childhood and adolescence that collect data on sleep and mental health using wearable or smartphone technologies. The aim is to provide a more objective measurement of insomnia and mental health in these younger age groups and to intervene early if needed
more studies involving people from diverse social and cultural background. Sleep practices are frequent culturally determined. Thus, research of different populations would provide a more complete picture of insomnia and mental disorders
greater recognition of people’s daily behaviors and environmental exposures and their contribution to insomnia and poor mental health. This includeseating fast food, disrupting sleep routines (for example, shift work) and excessive use of technology.
The results of this research will have profound implications for the accurate diagnosis and treatment of both insomnia and mental disorders. The aim is to reduce the weight when these conditions occur together, both for individuals and society wider.
If this article has raised issues for you or if you are concerned about someone you know, please call Lifeline on 13 11 14. Free update about insomnia and mental health is available from the Sleep Health Foundation.
