Worried Chronic Insomnia Can Kill?

The Effects Of Insomnia 

Insomnia is a prevalent and debilitating sleep disorder, affecting an estimated 770 million people worldwide. 

Symptoms include difficulty falling asleep or staying asleep, with this lack of sleep leading to fatigue, depressive symptoms, anxiety, impaired social functioning, and decreased wellbeing.

It is, by all accounts, a terrible experience.

Terrible enough for many people to wonder if insomnia can kill you.

After all, you can find lots of apparently accumulating evidence, including meta-analytic studies suggesting chronic insomnia is linked to various medical conditions, such as dementia, hypertension, type 2 diabetes, and inflammation. 

But surprisingly, despite all these suggested ways chronic sleep loss affects your health and creates health problems, it's not clear that there is any increased mortality risk, that is "risk of dying early" induced by all this time spent awake.

There are various theories that explain how individuals with insomnia might be at an increased risk of mortality, potentially stemming from psychological or physiological causes. 

In terms of psychological causes, multiple theories draw a connection between insomnia as a known risk factor for developing psychological disorders such as depression and anxiety. 

While the exact way in which this type of sleeplessness leads to the development of these psychological conditions is unclear, the theory is that these mental health issues can put individuals at a heightened risk of mortality due to the increased likelihood of self-harm and suicide behaviors.

Research has also suggested potential theoretical physical health causes for increased mortality rates with insomnia.

Several studies have demonstrated a heightened 24-hour metabolic rate, an overactive hypothalamic-pituitary-adrenal (HPA) axis, an activated sympathetic nervous system (SNS), increased heart rate, and reduced heart rate variability in those affected by insomnia. It has been suggested that this underlying strain from sleep deprivation is associated with hypertension, diabetes, and greater risk of death.

Yet despite plausible theories for insomnia increasing the risk of early death, actual real scientific evidence is inconsistent.

While some smaller-scale studies have suggested that insomnia may increase mortality risk, larger samples with follow up of over 28 years have found no evidence or even a negative association between mortality and insomnia. 

For example, Chien et al. and Vgontzas et al. noted an increased mortality rate for individuals suffering from insomnia after a 14-year follow up period. 

In contrast, Gapstur et al.'s prospective cohort study of U.S adults failed to find proof of a link between insomnia frequency and fatal prostate cancer at 28 years of observation.

Likewise, Kripke et al.'s sample of 1.1 million people showed a lower mortality rate with 6-year follow up in those who experienced symptoms of insomnia. 

Thus, the data is at best inconclusive.

Going Without Sleep.... 

In order to better understand the relationship between insomnia and early death researchers from Australia’s Flinders University and Adelaide Institute For Sleep Heath undertook a groundbreaking study, the first to use meta-analysis (a study of all the existing studies), to evaluate the evidence supporting an association between mortality and chronic insomnia.

What makes this study extra important is that they carefully defined chronic insomnia (CI) using actual diagnostic criteria.

Defining CI as insomnia symptoms occurring at least three nights a week for one month or more the researchers drew on the data from seventeen suitable studies with a combined sample size of approximately 37 million participants followed up for an average of 11.6 years. 

The findings? 

Overall, the researchers found no significant difference in mortality risk between those who reported insomnia symptoms and those who did not. 

In plain English: you won't die from lack of sleep resulting from experiencing insomnia.

The researchers stated:

These findings provide further support for the hypothesis that there is no link between increased risk of death and insomnia.

Further analyses taking into account factors including excessive alcohol consumption, smoking, obesity, and hypnotic use found:
- females had a reduced rate of mortality when compared to male patients;
- Studies with a shorter duration to follow-up and larger sample sizes, reported a lower rate of mortality among those reporting symptoms of insomnia compared to those who did not.

So CI could make you less likely to die according to some studies!

The researchers commented:

This meta-analysis revealed the risk of mortality did not differ significantly for those with symptoms of insomnia when compared to those without symptoms. The lack of an association between mortality and insomnia was also observed when using the most complete adjustment for potential confounders, as reported by the individual studies included in this meta-analysis.

Get Medical Advice..... (But Perhaps Think Twice About The Medicines)

But there was one interesting association between CI and early death:

• the use of hypnotics (i.e. sleeping pills) was associated with a small, statistically significant increase (6%) in mortality relative to those not taking hypnotic medication

The researchers noted:

“it likely that the insomnia group have a much higher usage rate of these medications and it is the medications which are associated with increasing mortality risk not insomnia” 

Given that those suffering from CI are often offered sleeping pills rather than the recommended first-line treatment CBT for insomnia, the researchers commented: 

“The current findings have significant implications for the treatment of insomnia. At present, the evidences does not support an increased risk of mortality from insomnia symptoms, even among those suffering from daytime impairments.....The current evidence reinforces the use of cognitive therapy, within a CBTi framework, as a frontline non-pharmacological treatment for insomnia... It is recommended treatment should focus on improvement of sleep efficiency, daytime symptoms and overall quality of life as addressed by CBTi. 

They also suggest sleep providers "reassure patients of no impact on their longevity as a consequence of their insomnia and altering the commonly held underlying belief that insomnia is detrimental to their health, a core cognitive feature of insomnia"

The study was published in the journal Sleep Medicine Reviews (Lovato & Lack., 2019).

Clinical Comment

Why do we keep hearing about how lack of sleep is so bad for your health?

At The Better Sleep Clinic we are often counselling patients that they need not worry that insomnia will harm their health but it can be hard to believe with so much noise from media reports and when it's so tough just to get through the day for many of our patients.

Why the discrepancies in evidence regarding the effects of CI on mortality?

The researchers note that it comes down to poor research studies (and these inadequate studies were screened out of this meta-analysis).

Research shortcomings are various and range from:
- small sample sizes (not a big enough study)
- a lack of control for confounders, such as smoking habits and medication use,
- high rate of attrition from studies; and
- limited effect size (i.e. statistically significant findings that are so small they are irrelevant to real life).

Even worse, insomnia is typically poorly defined by studies.

Many researchers don't have an understanding of clinical sleep disorders. Some studies only use a single question about “sleep problems” as evidence of “insomnia”.

Yet this doesn’t align with actual diagnostic criteria for CI disorder.

This means the findings don’t actually apply to people with real CI.

Likewise, the majority of research has been conducted using sleep duration, hours of sleep, rather than CI as the variable of interest. 

Insomnia is often associated with short sleep duration or a limited amount of sleep; however, this does not apply to all types of CI.

Insomnia is often associated with misperception of sleep state, duration and quality.

In fact, previous research has found that 57% of people with insomnia had an objective sleep duration of more than 6 hours. 

Similarly, Vgontzas and colleagues recorded an objective sleep duration exceeding 6 hours in 40% of their sample size of 55 individuals diagnosed with insomnia. This means many are physically getting adequate sleep even if they are unhappy with it.

Moreover, most studies failed to take into account the frequency and severity of insomnia when forming conclusions.

All these variations make much of the previous research either inaccurate or irrelevant.

It's hard for people to understand that most research on sleep is conducted by researchers who are not knowledgable about clinical sleep disorders, have no experience with sleep disorders, and are often confused about clinical disorders and fail to define them properly.

Even knowledgable researchers, for example Dr Matthew Walker, do not have real world experience treating sleep disorders.

This means they know very little worthwhile information for those with sleep disorders (I'm sure he knows a lot about sleep in healthy normal sleepers though).

So it’s important to pay attention to the difference between a researcher and a researcher with actual clinical experience.

This is research conducted by knowledgeable sleep clinicians and so represents the best actual information on clinically defined insomnia and premature death available.

And it's a sample size of 37 million followed for an average of 11 years.

And when actual clinically experienced practitioners conduct research, as with this study, it shows that sleepless nights due to properly defined chronic insomnia may be unpleasant but that's all they are: unpleasant.

 Insomnia alone won't kill you.

So there's no need to worry about the physical health effects of CI as they are rare (excluding the mental health effects which are quite common). 

In fact, this research suggests it is possible that insomnia may even extend your life - and given that sleeping a regular 8.5 or more hours is actually a lot worse than sleeping less than 6 hours that could make sense.

It's also worth pointing out that this study found that sleep medications, often what people experiencing insomnia resort to when they can't sleep, are more likely to be a cause of death (premature death) rather than the poor sleep itself.

This has been found in other studies.

Kripke and colleagues reported prescription sleeping pill use was significantly associated with mortality after control for insomnia in their large sample of over 1.1 million adults. Likewise Chen and colleagues found consistent, increased mortality risk among those who use hypnotics frequently, even after controlling for insomnia. 

The takeaway from all this information?

If you're struggling with ongoing insomnia and worried you aren't getting enough sleep you can take heart - CI, as unpleasant as it is, is unlikely to be harming your long term health.

But while insomnia won’t kill you, it is difficult to live with and studies suggest typically chronic insomnia doesn’t go away by itself.

We offer full cognitive behavioral therapy for insomnia (CBT-i) the first line recommended treatment for insomnia.

This includes supported medication tapers.

So if you need support, or you have questions about treatment then get in touch or book an appointment directly.

And don’t forget that, while we primarily see individuals suffering from insomnia, we also treat and support other sleep disorders such as circadian rhythm sleep disorders and restless legs syndrome.  

Article Author: Dan Ford Sleep Psychologist

Quick Facts On Chronic Insomnia And Mortality

Can Chronic Insomnia Kill You?

Different studies have found conflicting evidence that chronic insomnia can lead to an increased risk of dying from all cause mortality. However, the most accurate and comprehensive meta-analysis of studies that accurately defined chronic insomnia, covering approximately 37 million participants followed over an average of 11 years, found no evidence of an increased risk of mortality from chronic insomnia (Lovato & Lack, 2019).

Do Sleeping Pills (aka Hypnotics ) Increase Risk Of Death?

Studies by Kripke et al (2002), and Chen et al (2013), as well as a comprehensive meta-analysis by Lovato and Lack (2019), have all reported a slight increase in risk of mortality associated with hypnotic use.

Do Males Or Females Have a Greater Risk Of Dying From Chronic Insomnia?

A comprehensive meta-analysis of chronic insomnia and mortality by Lovato and Lack (2019) found that females had a reduced rate of mortality when compared to male patients.

Can Chronic Insomnia Reduce Your Risk Of Dying?

A comprehensive meta-analysis of chronic insomnia and mortality by Lovato and Lack (2019) reported that studies with a shorter duration to follow-up and larger sample sizes reported a lower rate of mortality among those reporting symptoms of insomnia compared to those who did not.