A very, very long day
Mr L is a 63-year-old engineer who presented to the sleep clinic with a life-long complaint of very short sleep. He remembers as a child that his parents would put him to bed at 8 p.m. every night and he would lie awake for hours before falling asleep. He would then wake very early in the morning and when he was going to school, he would be up, dressed and finished breakfast before his father, a bus conductor, left for work at 6 a.m.
Initially he tried to increase his sleep time by staying in bed with the lights off, but he found this increasingly frustrating and took to reading with a pocket torch until his parents fell asleep, at which point he would turn the light on and read until he felt sleepy. He felt this sleep pattern actually gave him an advantage over his classmates, as he was able to read and study for several hours more each day. His parents, however, were extremely concerned about how the lack of sleep would affect him and they took him to a succession of doctors, some of whom prescribed antihistamines as hypnotics. These did increase his sleep time, but he always felt groggy the next day and his sleep returned to baseline as soon as the course of medication was finished.
When Mr L went to university he had to work a late-night job to fund his studies while attending classes during the day. He found this fairly easy, as he only slept five hours a night and felt alert and focused during the day. He did not feel particularly anxious about his short sleep, as many of his peers were burning the candle at both ends, though they generally needed to nap during the day to maintain that lifestyle. Indeed his sleep was not an issue until he got married in his thirties. His wife would sleep eight hours a night, and he naturally tried to go to bed at the same time and rise at the same time as her. However, he was never able to match her sleep time and he and his wife became increasingly anxious about his relative lack of sleep. Once again he was tried on a number of hypnotics and sedative antidepressants. These increased his sleep time slightly, but the daytime fatigue he experienced led him to discontinue all of them.
As he grew older his sleep time gradually reduced from five hours to three hours. He denied any daytime fatigue and indeed ran a very successful business, played tennis twice a week and was in good health. His primary complaint with his sleep pattern was that he would go to bed at the same time as his wife and lay awake feeling frustrated for most of the night. He also frequently travelled for business and would be awake for much of the night in his hotel room, feeling extremely bored. He was therefore keen to increase his sleep time to fit better with his lifestyle.
1 Does Mr L have insomnia?
2 Is it possible to be a short sleeper and have insomnia?
3 What are the causes of short sleep?
4 How would you treat Mr L?
1. Does Mr L have insomnia?
There are a number of different definitions of insomnia depending on which classification system one is using, e.g. DSM, ICD or the International Classification of Sleep Disorders.
However, what they all have in common is that insomnia is considered a difficulty in initiating or maintaining sleep, or poor sleep quality, with daytime symptoms and/or distress about sleep. The daytime symptoms are most commonly tiredness (though very often not sleepiness), poor concentration, irritability, low mood, headache and lack of energy or motivation. It could be argued that Mr L has difficulty initiating and maintaining sleep, as he is unable to sleep for as long as he wants, and he is distressed by his sleep and therefore would meet criteria for insomnia. But the absence of daytime symptoms is a strong indicator that he is getting as much sleep as he needs. One could therefore argue that he does not have insomnia, but rather is a naturally short sleeper. This is borne out by the life-long history of short sleep without any daytime dysfunction.
2. Is it possible to be a short sleeper and have insomnia?
Yes. It is a very widely accepted and deeply ingrained perception that we need eight hours’ sleep a night. Therefore, when someone is, for example, a six-hour sleeper, they will often try very hard to sleep for eight. They will spend eight hours in bed, but of course will spend two hours awake. This may raise their anxiety about their sleep, as they became worried about why they cannot sleep the full eight hours. They come to associate the bed with the frustrating experience of lying awake and, when they do sleep, their sleep may be light and broken, as they are ‘trying to spread six hours sleep over eight hours’. As a result of this anxiety and the negative associations with the bed, their sleep may well deteriorate, leading to insomnia on top of the short sleep.
3. What are the causes of short sleep?
There are three reasons why someone may have a short sleep period:
◆ Insomnia—the person needs more sleep but is unable to get it despite having adequate sleep opportunity. It may be caused by anxiety, pain, depression, poor sleep-related behaviours, physical illness, etc.
◆ Sleep deprivation—the person needs more sleep but is unable to get it due to inadequate sleep opportunity. This could be due to lifestyle factors such as long working hours, studying late, etc., or due to external agents that prevent sleep, such as noise or being kept awake by another person.
◆ Short sleep need—the person only needs a short sleep time to feel well. They do not suffer any ill effects from their short sleep, nor does increasing sleep opportunity lead to an increase in sleep time. It is not clear why some people need less sleep than others. The average sleep time for adults in the West is around 7.5 hours, but as this is an average there will naturally be some whose sleep is longer and some whose sleep is shorter. Mr L is obviously a fairly extreme example, but we would expect there to be a handful of normal people who are unusually long sleepers or unusually short sleepers.
4. How would you treat Mr L?
Given that he had no daytime symptoms, we reassured Mr L that, although his sleep time was unusually short, he was getting enough sleep for his needs. There was therefore no need to try to increase his sleep time from a health perspective. We spent considerable time explaining that there is no ‘normal amount’ of time to sleep and that there is always going to be variability around the mean. The right amount of sleep for any particular person is the amount that allows them to feel well and alert for most of the day most days (as no one feels alert all day every day). As Mr L was feeling alert most of the day most days on three hours sleep, that was the right amount of sleep for him. He found this very reassuring, as, although he had not voiced it in the initial assessment, he was afraid that his short sleep was somehow damaging him, or a sign that he was abnormal.
However, he still wished he could sleep longer. We agreed to give him a course of cognitive behaviour therapy for insomnia (CBT-I), which he found useful although it didn’t increase his sleep time. As part of the CBT-I we taught him sleep scheduling and explained that he should not go to bed earlier than five hours before his rising time. He should also not go to bed until he was feeling sleepy. His wife was very anxious about this routine, and so we invited her to attend the clinic with Mr L so we could explain the rationale behind this approach and help them work out, as a couple, how to accommodate this new schedule without disrupting their relationship or Mrs L’s sleep. They reached a compromise whereby Mr L would go to bed with his wife and stay with her until she fell asleep. He would then get up and use the extra time in his day to engage in relaxing, enjoyable activities and going back to bed when he reached his threshold time and was sleepy.
At follow-up Mr L was feeling much less anxious about his sleep. He said it was a relief not to feel that he had to spend eight hours in bed and remarked that at age 63 he had at last been given permission to stay up late. His only complaint was that now he had so much more time in the day that he was struggling to find things to occupy him for his 21 hours of wakefulness. However, on balance he felt it was not a bad problem to have. Although his total sleep time had not increased at all, as he was no longer distressed about his sleep he no longer had insomnia.
Learning points
There is no ‘right’ amount of sleep. Each person’s needs are different (and can change with time). The common perception that we all need eight hours’ sleep is not true. The acid test is how the person feels during the day. If they are alert and feel well most of the day most days, they are getting enough sleep for them.
However, one can be a short sleeper and have insomnia on top of the short sleep. Indeed the constant striving by short sleepers to achieve the mythical ideal of eight hours’ sleep may raise their anxiety and precipitate the insomnia.
There are three reasons why someone may be a short sleeper. Some people simply need less sleep (short sleepers), some need more sleep but are prevented from getting it by lifestyle or environmental factors (sleep deprivation), and some need more sleep but are unable to get it despite adequate opportunity and the absence of environmental factors (insomnia).
If someone is a short sleeper but does not have daytime symptoms, then reassurance that they are getting as much as sleep as they need is often the only intervention they require.