What Causes Insomnia?

Source: Ben White, 165045/unsplash

In the previous post, we considered why insomnia is not the same as sleep deprivation. But what is insomnia, then? The question as to the underlying cause of sleeplessness is very common in clinical sleep practice. People suffering from chronic sleep difficulty come up with answers based on their own experience. In his seminal book Insomnia: Psychological Assessment and Management (1993), Dr. Charles Morin, a leading insomnia specialist, cited then-current research indicating that people most frequently blamed the overactive mind for their difficulty sleeping. A more recently published study on causal attributions (2013) similarly found that insomnia patients most frequently identify the inability to shut off thoughts, stress, and worrying about sleep as causes of their insomnia. Ideas about causes of insomnia guide patients’ views on treatment options (2013) and determine their successful adaptation of the recommended therapeutic techniques (2015a).

Consider the following hypothetical example. A person – let’s call him Jake – has been struggling with insomnia for many years. Jake knows that even if he feels very tired, his mind kicks into gear as soon as he gets into bed. He just can’t stop thinking about all kinds of things, usually worrisome, including how poorly he is going to function tomorrow if he doesn’t get a good night’s sleep. To quiet this mental conundrum, he starts watching a video on his tablet and after about an hour finds himself nodding on and off. But as soon as he shuts down the tablet, his mind becomes active again, so he keeps videos running by the bedside most of the night. Jake has read on the internet that electronics in bed should be avoided, but the advice does not make much sense to him, because running videos helps quell the cause of his insomnia – excessive ruminations. As his sleep is not getting better, he decides to look for professional advice. His primary care doctor recommends to worry less and to exercise more. A pulmonologist tests him for sleep apnea. A psychiatrist evaluates him for depression and anxiety. A therapist offers to work on unresolved conflicts and to develop better stress-coping skills. Jake has always been a bit of a “night owl,” but he remembers that the real trouble sleeping began soon after he went through a divorce about 10 years ago. He has been in a happy new relationship for a few years now, and the divorce is very much a thing of the past. Or is it? With his head spinning, Jake returns to running videos at night and going heavy on espressos during the day.

Jake thinks that his insomnia has one, perhaps two underlying causes, and if those causes are eliminated, sleep should return to normal. Thinking of disturbed sleep like of a malfunctioning car, Jake believes that all one has to do is to identify and replace the broken piece. Sleep, unfortunately, does not work in such a linear fashion. Although numerous medical and psychiatric conditions can disturb sleep, insomnia may not directly relate to physical or psychiatric symptoms (2014), and often persists after successful treatment of the “primary” condition (2007). Moreover, insomnia can predict future symptoms of medical (e.g., chronic pain, 2010) or psychiatric (e.g,. depression, 2018) conditions. On the bases of this type of evidence, current editions of the Diagnostic and Statistical Manual (2013) and the International Classification of Sleep Disorders (2014) recognize chronic insomnia as an independent condition that may co-exist with other conditions.

As a condition in its own right, chronic insomnia has a multifaceted nature. As early as 1987, another world-renowned insomnia specialist, the late Dr. Arthur Spielman, with his colleagues, proposed the “3P model”, which since has been referenced essentially in every text concerned with causes of insomnia (e.g., 2015b). This model separates all possible causes into three groups of factors: predisposing, precipitating and perpetuating. Predisposing factors are physical and psychological qualities that make one’s sleep vulnerable, for example, being a light sleeper or a “go-getter.” Precipitating factors are life events that acutely disturb sleep, such as an illness or a jet lag. As a person attempts to cope with a period of poor sleep, certain strategies that may be briefly helpful become factors perpetuating insomnia in the long run. Thus, spending more time “trying” to sleep or distracting oneself with electronics from bedtime ruminations very quickly become major culprits on the road to recovery.

Thinking of insomnia in this fashion places it in a category with other conditions that are considered life-style-related. For example, what causes hypertension? Stress? Genetics? Excessive worrying? Perhaps another medical condition? Could lack of exercise or poor dietary choices be the cause? It’s easy to realize that to treat hypertension optimally, one should adequately address multiple possible reasons for it. A similar approach to insomnia is advised by the “3P model.”

In our hypothetical example, Jake’s being a “night owl” is a biologically based predisposing factor. It wasn’t particularly problematic before he developed full-fledged insomnia, but now it needs to be addressed. The divorce was likely a precipitating factor, and if Jake does have any lingering feelings about it, that should be worked through as well. His current sleep-related habits include running videos while in bed at night and keeping alert with caffeine during the day. Habits such as these might help him on a single night or a single day, but with certainty they continue hurting his sleep more and more in the long run, and must be changed. And last but not least, the search for a single “cause” that can be quickly “fixed” has to be replaced with more realistic understanding of multiple contributing factors and a unified long-term strategy.

If this sounds like work, it’s because it is. But taking this route with CBT-I has a great evidence-based reward – a sustained improvement in sleep and a renewed sense of self-efficacy as a good sleeper!