Henry Nicholls is more qualified than most to write about the science of sleep. At the age of 21, he was diagnosed with narcolepsy – a rare disorder that causes people to fall asleep without warning. But, he tells us, it’s a largely misunderstood condition.
What exactly is narcolepsy?
Most people know that those with narcolepsy have an irresistible need to sleep at inappropriate moments during the day. This was my first symptom when I was diagnosed – I’d find myself dozing through tutorials at university and overdosing on caffeine.
But that’s probably the least interesting of the symptoms. Most people with narcolepsy also experience cataplexy, which is where the emotional centre in the brain causes a sudden loss in muscle control. It’s the same process that happens during sleep to stop you acting out your dreams, but during the day, it can mean that even a small emotion has you collapsed on the floor.
What triggers it?
It can be any emotion, but the most common trigger is humour – I have a friend who only needs to raise an eyebrow to have me on the floor. What’s fascinating is that you retain consciousness throughout. You’re in a crumpled heap on the floor, laughing your head off inside, but you just look asleep or dead. And then someone comes up and says, “Is he okay? Does he need an ambulance?”. That’s even funnier, and it keeps you under for a while longer.
The attacks usually last only 10 or 20 seconds, but there’s very little warning, and it can be exhausting. If you’re collapsing 100 times a day, it can be an extremely disabling condition where you become fearful of leaving the isolated safety of your home.
What are the other symptoms?
Many people with narcolepsy also experience sleep paralysis and hallucinations when they’re waking up or dropping off. It happens when the brain is in rapid eye movement (REM), dreaming sleep, but you’re awake, unable to move. The brain often manufactures petrifying visions.
I used to see an axe murderer – I’d feel the axe as it slammed into my chest, and the blood trickling down my sides. Paradoxically, people with narcolepsy tend to experience fractured night-time sleep too, waking up as many as 20 or 30 times a night: it destroys your sleep quality.
What causes narcolepsy?
The vast majority of cases are caused by an infection such as flu or, as in my case, a streptococcal infection. The immune system destroys the invaders, but in some cases it also takes out a population of cells in the brain’s hypothalamus that produce proteins called hypocretins, which play a crucial role in sleep regulation. At the moment, there’s no cure, because once you’ve lost these cells they’re gone.
We’re only able to treat the symptoms. There are stimulants such as modafinil and dexamphetamine that help to keep us alert, and small doses of antidepressants can treat the cataplexy. I’ve found drugs to control most of my symptoms, but I’m fortunate – not everyone responds to them.
How common is narcolepsy compared to other sleep disorders?
At any one time, chronic insomnia affects about 10 per cent of the population. Sleep apnoea is the other common one, which is when a person’s breathing is interrupted during sleep – snoring is often a sign of this.
Narcolepsy is a rarer disorder, affecting about 1 in 2,500. There are stories of people going 20, 30, even 60 years before being diagnosed, by which time the psychological damage can be serious. We still need to get much better at spotting these disorders.
Why is it so important to get good sleep?
Sleep is doing so many things for us: it’s strengthening connections in the brain, making new ones, pruning ones we don’t need. It’s a time to replenish and recharge. Chronic sleep deprivation puts you at greater risk of a whole host of conditions: cancer, stroke, type 2 diabetes, depression, hypertension, obesity, the list goes on. It’s no coincidence that every organism on Earth with any kind of neural cluster resembling a brain performs something akin to sleep.
Any top tips for a decent night’s sleep?
This isn’t going to be popular, but the most important thing you can do is stick to a routine. That means going to bed and waking up at the same time every day, even the weekend! For insomnia, my trick is to repeat a neutral word like ‘the’ over and over – not out loud, but in your mind. You’ll find that your brain can’t think about anything else, and racing thoughts will stop.
I’ve managed to get snatches of good sleep now for the first time in 20 years, and it’s been so empowering. That’s the upbeat revelation of this book – we really can change our sleep habits, even those of us with sleep disorders.