When sleep controls your life: Insomnia, productivity and mental health
Most people have some experience with sleep difficulties. But for some, insomnia is a constant, life-defining battle. One in 14 South Africans suffer from the sleep disorder, which is tied to mental illness, a new HSRC study suggests. By Andrea Teagle.
As an adult, Emily has never known what it is like not to have insomnia. She struggles to sleep most nights – usually dropping off at around 1 or 2 am – wakes up several times and rises early, even if she is exhausted. After many days of negligible sleep, Emily describes attempting to wake up as “physically painful”. Insomnia has tentacles in every domain of her life: routine, work, exercise and social. It impairs her concentration, her playfulness, her emotional resilience and her ability to recover from illness. When it is at its worst, she says, “it’s like your insomnia controls your life.”
Last year, HSRC researcher Prof Karl Peltzer and Prof Supa Pengpid from Mahidol University, in Bangkok, estimated that about 1 in 14 (7.1%) of people in South Africa over the age of 15 experience insomnia. The study used data from the national, cross-sectional South African National Health and Nutrition Examination Survey (SANHANES-1) 2012, which asked 15,133 individuals questions relating to non-communicable diseases such as insomnia. The probability of experiencing insomnia increases steadily with age: among participants over 65, 1 in 5 (20.5%) had suffered from it in the last month.
At a societal level, insomnia can lead to economic losses, mainly due to lost productivity, but also because of the negative health effects associated with insomnia.
A 2009 study in Quebec, Canada, which is just over 6 times smaller than South Africa in terms of population, estimated that the economic costs of insomnia to the country in 2002 was $6.6 billion – about 1% of its GDP for that year.
Three quarters of these costs were due to lost productivity and absenteeism. While these costs are not generalisable across countries, they give an idea of the scale of the problem.
Chronic insomnia might also affect an individual’s day-to-day performance, career choices and career progression. Two years ago, Emily, who is a doctor, made the decision to pursue medical research instead, as it affords greater flexibility to work around her insomnia.
“It was the hardest decision of my life,” she recalls.
Impact on health
Peltzer and Pengpid found significant positive correlations between insomnia and a range of physical and mental health indicators. The mental health indicators included psychological distress, having experienced three or more traumatic events, and partial post-traumatic stress disorder (PTSD).
Seventeen percent of participants reported psychological distress, 20% had experienced one or more traumatic events, and 4% had PTSD symptoms. It is hardly surprising that these individuals might experience trouble sleeping. But to what extent does the relationship work in the other direction? How does insomnia affect an individual’s risk for or exacerbate, mental illness?
That question is a little trickier to answer.
Firstly, differences in defining and diagnosing insomnia cause estimates of prevalence to vary widely. A quick Google search might turn up prevalence rates anywhere between 10% and 60% for adult populations. Peltzer and Pengpid used daytime consequences as a diagnostic criterion, and participants responded to questions pertaining to the past month. However, other definitions might not include daytime malfunctioning, and estimates of insomnia might refer to the proportion of a population that has experienced insomnia at any point over the last year or at any given time, etc.
The criteria used by Peltzer and Pengpid were similar to that of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM 5) criteria, which included significant impairments in social, occupational, educational, academic, behavioural or other important areas of functioning.
Even when we are clear on the criteria, cross-sectional, “snapshot” studies like Peltzer’s cannot determine the direction of causality. Are individuals at risk for insomnia because they have depression? Or are they at risk for developing depression because they suffer from insomnia? Or could it be that the same stresses – the chronic stress of poverty, for example -- that triggered depression in an individual also caused insomnia? Imagine a snapshot of two friends looking at each other angrily. You suspect a causal relation, but you can’t tell who started the fight or whether both are responding to something else not in the photo. This is why researchers include other likely factors in their analysis.
In accordance with other research, Peltzer’s study found that women tend to have higher rates of insomnia than men, and that this difference increases with age. However, this was not statistically significant after adjusting for other factors, like health, diet and exercise. Similarly, after adjusting for health variables, age is no longer a predicted risk.
Peltzer and Pengpid recommend that primary care facilities adopt strategies for facilitating the diagnosis and treatment of insomnia among target groups. Cognitive behavioural therapy has been shown to help alleviate insomnia, by assisting people to better process negative thoughts and stop cycles of anxiety that exacerbate the problem.
Emily says that tips like staying away from screens – which disrupt the body’s circadian rhythm by mimicking daylight, a cue for wakefulness – and exercising regularly do help. She has also recently enrolled on an online, evidence-based treatment programme called Sleepio that aims to improve an individual’s relationship with sleep.
“You get into a state where you feel like you haven’t slept, and it perpetuates,” Emily says. “Keeping a sleep diary is supposed to help you recognise that, even if you’re only getting a few hours of sleep, those few hours are very beneficial…It made me feel like I was a bit more in control.”
Author: Andrea Teagle, HSRC science writer