What is insomnia?
Insomnia is the difficulty in falling asleep, staying asleep, or waking early.
It causes poor daytime functioning including poor concentration, mood disturbance, and fatigue. It’s extremely common, with around 10% of the adult population suffering from it at any one time.
Having an occasional bad night’s sleep is something we all experience from time to time and is actually perfectly normal, but insomnia is when this becomes a more consistent issue and with a greater impact on day-to-day functioning.
What impact does insomnia have on my health?
The health impact of poor sleep cannot be overstated.
We all know how we feel after a bad night’s sleep – tired, irritable, forgetful, low in mood. When this happens night after night the impact can be profound. You end up feeling dreadful all the time and quality of life can drop through the floor. There can be a significant knock-on effect on the relationships with your partner and family, with your work, and with your health.
Poor sleep reduces your productivity and can cause strain at work, especially if co-workers feel they have to take up the slack, which puts further strain on relationships. Poor sleep can mean you miss work, and when you’re in work you’re more likely to have an accident. And most worrying of all – is the risk of a road accident.
Insomnia is known to impact your mental health and can cause, or exacerbate depression and anxiety.
Habitually sleeping for only a few hours each night increases the risk of heart disease, stroke, and diabetes. The impact of poor sleep on your health is discussed in more detail here.
What are the causes of insomnia?
There are a number of ideas about what actually causes insomnia, but the idea that explains insomnia for the vast majority of people is rooted in the roles of worry, stress, and anxiety in preventing sleep.
The reason for this is based largely on evolution. Humans, like most species, are extremely vulnerable as they sleep. Our eyes are closed, we are not perceptive to sounds and our bodies are completely relaxed – literally any predator could just wander up and eat us. To avoid this happening, any perception of any danger at all, such as a saber-toothed tiger prowling around the mouth of our cave, will cause a profound response in our bodies so that we are fully awake and fully alert. We are certainly not going to fall asleep.
Nowadays, with secure houses to sleep in (and fewer saber-toothed tigers) we don’t have the same exposure to deadly threats. But what we do have are other lower stresses and worries, that are lower in intensity than the tiger, but still on that same spectrum of worry and with the same potent ability to prevent sleep.
And it can be any of a wide range of worries that keep us up. These can be short-term or one-off events such as worries about a job interview the next day, or fretting over an exam. Or they can be longer-term worries about health, stressing about finances, or due to a diagnosed anxiety disorder.
What are the three P’s?
In 1987, a researcher called Spielman made an excellent explanation of the reasons for insomnia called The Three Ps.
The first P is predisposition. This is your normal, baseline likelihood for getting insomnia. Factors that contribute to this are really varied and might include being a light sleep, personality characteristics such as a tendency to stress, worry or anxiety, or even having a small bladder so you have to get up to pass water many times overnight. The predisposition is different for everyone and is shown by the blue sections in the chart below.
The second P is precipitating. This is a life event that happens that pushes you over the threshold and triggers insomnia. These could be stressful events, such as a divorce or bereavement, or factors related to your health. They can also be events that disrupt your sleep for other reasons, such as having children or starting shift work. Whatever the cause, something happens that upsets the apple cart and stops you from getting to sleep.
The third P is perpetuating. Perpetuating factors are things that keep the insomnia going. These factors are usually things we do that are meant to help us deal with excessive daytime sleepiness – things like napping during the day or drinking lots of caffeine. You can see these factors introduced in the Early-Insomnia column. But (and this is the interesting bit) by Chronic-Insomnia, the original stress that precipitated insomnia has reduced to a sub-threshold level, but what keeps us over that insomnia threshold are actually the behaviours that were originally meant to compensate for insomnia in the first place.
Other perpetuating factors alongside those intended to compensate for daytime sleepiness include the process of becoming habitualised to not sleeping – it becomes the new norm. With chronic insomnia, you get used to lying awake in bed at night and lose the association of the bed meaning sleep. With insomnia, it is common to develop sets of false beliefs around sleep such as feeling your insomnia has a genetic cause and so it cannot be fixed. Or thinking, if you don’t get eight hours of sleep, you won’t be able to function. Neither of these statements is true, and they prevent people with insomnia from getting better sleep.
There can be other reasons for insomnia besides this. Sometimes just having a mind that won’t turn off, or a strong compulsion to think, means you can’t sleep.
Another thing to mention on the drivers of insomnia is that lying awake at night when the rest of the world sleeps when you have a job interview, or exam, or something else important the next day - is unbelievably annoying! And the more annoyed you get – the more stressed, worried, and anxious - the less likely you are to fall asleep. You end up stuck in a rut of struggling to sleep, then worrying about sleep, then struggling even more to sleep.
What is the best treatment for insomnia?
Fortunately, there are effective treatments for insomnia, and the most effective of these is called cognitive behavioural therapy for insomnia, or CBT-i. CBT-I is a collection of different treatments that are aimed at the unhelpful thought (cognitive) processes around sleep and the various routines (behaviours) that reinforce poor sleep.