Insomnia: Causes, Impacts and Treatments

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 widespread, with around 10% of the adult population suffering from it at any time.

Having an occasional bad night’s sleep is something we all experience from time to time and is perfectly normal. Yet, insomnia is when this becomes a more consistent issue affecting at least three nights a week and usually for at least three months.

The impact of insomnia

The word insomnia means ‘can’t sleep’, and understandably there is a significant focus on the nighttime symptoms of not sleeping. However, the impact during the day usually causes most of the problems.

We all know how we feel after a bad night’s sleep – tired, irritable, forgetful, and low mood. When this happens night after night, the impact can be profound. You end up feeling like a perpetual zombie, with your quality of life dropping through the floor. There can be a significant knock-on effect on your relationships with your partner and family, work, and health.

Insomnia: Causes, Impacts and Treatments

Poor sleep reduces productivity and can cause strain at work, especially if co-workers feel they have to take up the slack, further exacerbating relationships. Insufficient sleep causes higher rates of absenteeism and, more worryingly, is associated with a higher risk of workplace and road traffic accidents.

Insomnia is known to impact your mental health. It can cause or exacerbate depression, anxiety, and other conditions. Habitually sleeping for a few hours each night causes an increase in heart disease, stroke and diabetes. The impact of poor sleep on your health is discussed in more detail here.

Causes of insomnia

There are several 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 mainly based on evolution. Humans, like most species, are highly 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 sabre-toothed tiger prowling around the mouth of our cave, will cause such a profound response in our bodies so that we are fully awake and fully alert. We are certainly not going to fall asleep.

Insomnia: Causes, Impacts and Treatments

Nowadays, with secure houses to sleep in (and fewer sabre-toothed tigers), we don’t have the same exposure to deadly threats. But we have other stresses and worries that are lower in intensity than the tiger, but still on that same spectrum of anxiety 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.

The Three Ps

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 potential for insomnia. Factors that contribute to this are varied, including personality characteristics such as your predisposition to worry and anxiety, as well as things like being a light sleeper or even having a small bladder, which means you have to get up to pee many times overnight. The predisposition is different for everyone and is shown by the blue sections in the chart below.

Insomnia: Causes, Impacts and Treatments

The second P is precipitating. This is a life event that happens that pushes you over the threshold and triggers insomnia. These are usually stressful events, such as a divorce or a 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 has happened that upset the apple cart and stopped you from getting to sleep.

The third P is perpetuating. Perpetuating factors are things that keep insomnia going. These factors are usually things we do that are meant to help us deal with excessive daytime sleepiness – 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 the insomnia has reduced to a sub-threshold level, but what keeps us over that insomnia threshold are the behaviours that were initially 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 false beliefs about sleep, such as feeling your insomnia has a genetic cause, 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 accurate, and they prevent people with insomnia from getting better sleep.

Insomnia: Causes, Impacts and Treatments

Lying awake at night, when the rest of the world sleeps, when you have a job interview, exam, or something else important the next day is very, extremely, incredibly annoying! And the more annoyed you get – the more stressed, worried and anxious you are – the less likely to fall asleep. You end up stuck in a rut of struggling to sleep, worrying about sleep, and then struggling even more.

And anxieties about sleep are not just at night but can continue during the day. And the challenge that poor sleep brings to personal relationships, work and health makes it feel like the wheels are starting to fall off your entire life!

So, what can be done?

Cognitive behavioural therapy for insomnia

Fortunately, there are effective treatments for insomnia. The most effective of these is called cognitive behavioural therapy for insomnia, or CBT-i.

CBT-i is a collection of treatments aimed at the unhelpful thought (cognitive) processes around sleep and the various routines (behaviours) that reinforce poor sleep.

The different components usually comprise an element of education on sleep, so the backdrop and context can be understood.

Sleep hygiene is a part of CBT-i but by itself is not an effective treatment for insomnia. Sleep hygiene lays an essential foundation for the other components of CBT-I, such as ensuring your bedroom is dark and quiet.

Insomnia: Causes, Impacts and Treatments

Cognitive components include reducing unhelpful thoughts and false beliefs about sleep. Behavioural elements include some grand titles, like ‘stimulus control therapy’, which involves strengthening the association of the bed meaning sleep. In addition, ‘sleep restriction’ sounds counter-intuitive, but it means reducing the time in bed to increase your drive for sleep, so you fall asleep quicker and don’t wake up overnight.

CBT-i takes commitment but is effective for short-term and long-term insomnia.

Sleeping tablets

There is always lots of discussion around the role of sleeping tablets. The general position is that short courses can be helpful in acute insomnia. Still, they are not effective for long-term insomnia. This is mainly because they don’t address the key perpetuating factors for chronic insomnia.

If you have insomnia, then look for ways to access CBT-i. We offer these both as 1:1 and group sessions on

Insomnia: Causes, Impacts and Treatments