Sleep Well Clinic medical director Alex Bartle explains insomnia and puts to bed those sleep myths.
What is insomnia?
Insomnia is an increasing concern in our Western society. Internationally, chronic insomnia, lasting for longer than one month, affects between 10 and 20 per cent of the adult population. Transient insomnia, however, affects most of us at some stage in our lives, and is much less likely to impact our health. A New Zealand study, published in 2004, indicated that 25 per cent of the studied population had suffered from insomnia lasting longer than six months, and 13 per cent suffered from insomnia with associated excessive daytime sleepiness.
Insomnia can be defined as difficulty with falling asleep (onset) or staying asleep (maintenance), or early morning waking that affects how you perform at home or work in the daytime. Another description of insomnia is ‘hyperarousal syndrome’ and many insomniacs will describe having an overactive mind. There are a number of risk factors for insomnia, the most common being stress and anxiety. Other risk factors include being female, older, single, unemployed and having a number of medical complaints. The fatigue associated with insomnia potentially harms mental and physical health (see medical and psychological issues associated with insomnia, below).
It’s 2.30am and you can’t sleep. Your mind is racing, and you have a busy day ahead of you. Panic is setting in. You toss and turn. Your heart races and you sweat. This is the third time in a row that you have been awake in the night, unable to switch off and sleep. Now, even two or three hours before bedtime, you have become anxious, knowing that another night of insomnia is ahead. How is it going to impact your family, work and health?
How does sleep work?
The human sleep-wake cycle is dependent on two concurrent influences which interact and balance each other: the circadian process and the homeostatic process.
The circadian process is a sort of internal clock that regulates alertness levels. It is dictated by the production of two hormones: melatonin and cortisol. Your circadian rhythm is also influenced by daily routines, such as work, meal times, regular exercise and regular social activities. But, by far the most powerful influence is the light and dark cycle, which influences the production of melatonin at night and cortisol in the morning.
Homeostasis, as it affects sleep, is the accumulation of sleep-inducing substances in the brain. Simply put, the longer you are awake, or the poorer your quality of sleep, the sleepier you become.
Is it really insomnia?
Sometimes people are diagnosed with insomnia when something else is actually going on. Delayed sleep phase syndrome is a circadian rhythm often referred to as ‘social jet-lag,’ and is common in teenage years and the early 20s. If you have a teenage daughter or son, you may have noticed they have significant difficulty falling asleep at an acceptable hour, but can sleep in in the morning if allowed, resulting in a normal length of refreshing sleep. But, if they have to get up early for work or study, they will have less time for sleep. Because they can’t fall asleep early enough, they can end up with a diagnosis of insomnia.
How is insomnia treated?
Treatments can be divided into two categories: chemical and behavioural.
Chemical treatments include prescribed sleeping tablets, and products bought from a pharmacy that are promoted as assisting with sleep. Be aware that up to 50 per cent of anything you take for sleep works as a result of the placebo effect. In fact, most pharmacy-based products are mainly placebo. The exception is Valerian, which acts as a very weak tranquiliser, and antihistamines, which are usually sedative but can leave you feeling groggy in the morning. Melatonin, taken as a sleeping pill, rarely works if you are under 55 years old, but may make you tired. Melatonin can be helpful when taken for jetlag. Prescription sleeping tablets are likely to be more effective but, as with all tablets taken for sleep, they become less effective with time, and you need to take increasing amounts in order to sleep.
Behavioural treatments are by far the most effective, but are reliant on you changing your behaviour around sleep, and understanding why. These include:
1. Sleep hygiene, which is important but, by itself, is often not enough (see below).
2. Stimulus control means bed is for sleep. The implication being, if you are not asleep within about 20 minutes, you should not be in bed. Get up for 15 to 20 minutes, and do something quiet and relaxing (not TV, computer, smartphone or talkback radio) before returning to bed.
3. Finally, sleep scheduling which is also known as bed restriction therapy. This is designed to improve sleep efficiency, or the time in bed that is spent asleep. If you are in bed for eight hours and think that you are sleeping for only four hours, that equates to a 50 per cent efficiency. To increase that efficiency, you can either take sleeping pills, which will eventually become ineffective, or reduce the time in bed. If you are in bed for only five hours, and sleeping for four hours, that is an 80 per cent efficiency, and bed is becoming a place for sleep and not anxiety. This process should be undertaken with the guidance of a sleep specialist.
In all cases, it is ideal to spend at least half an hour outside in the morning light which is designed to suppress melatonin, and wake us up. In fact, the more time we can spend outside in the day the better, but especially in the morning.
Insomnia seems to be a growing problem and may, in part, be the consequence of increasing use of electronic media close to bedtime or in bed. It’s not just the blue or green light that suppresses melatonin (this can be filtered out with an app), but the engagement with the device. That is why television is not so bad, and reading is best.
Help with the behavioural strategies for insomnia can be found at many of the sleep clinics in New Zealand, and through some psychologists. There are also some good online resources, including Harvard Health’s SHUTi and the Sleepio programme.
Medical issues associated with insomnia
- Associated with increased risk of heart disease
- Mounting evidence for links to hypertension
- An association between disturbed sleep and breast, colorectal, prostate, oral and nasal cancers has been found in studies over recent years
- A US study of 1741 people found chronic insomnia was associated with increased type 2 diabetes risk
- A strong association has been found between disruption in sleep and gastrointestinal disease
- Somewhat counter-intuitively, sleep disorders can cause urinary problems, such as nocturia, a condition in which you wake at night because you have to urinate
Psychological issues associated with insomnia
- Impaired cognitive function
- Excessive fatigue
- Poor concentration
- Learning and memory difficulties
- Personality changes and irritability
- Hyperactivity in children
- Avoid caffeine in the late afternoon and evening
- Avoid cigarettes completely, or within two hours of sleep
- Limit alcohol consumption – any more than two units is initially sedative, but later becomes a stimulant
- Avoid a heavy or spicy meal within three hours of bedtime
- Exercise regularly, but not within three hours of bedtime
- Allow at least one hour of relaxation time to unwind before bedtime
- The bedroom should be quiet, dark and comfortable and around 16-18°C
- Maintain a regular sleep/wake schedule
- Avoid clock-watching overnight
- Try journaling: write down anything that is worrying you, then discard
- Finally, especially if the concern is sleep-onset insomnia, try going to bed later rather than earlier.
Sleep myths busted
There are a number of myths concerning sleep that you don’t need to lie awake over.
An hour of sleep before midnight is more valuable than an hour after midnight. Midnight is a social concept. Daylight saving changes midnight twice a year anyway. Sleep is associated with production of melatonin and cortisol, not the time.
We should be able to sleep through the night uninterrupted. Almost everyone will wake during the night at some stage. Just before we fall sleep, we have two or three minutes of amnesia. Therefore, the common occurrence of waking for a minute or two then returning to sleep in the night will not be recalled. As we age, that period of wakefulness becomes longer, and we will be more aware of waking. Some report that they have not slept at all for many days, but insomnia is so subjective there is a common condition known as ‘sleep state misperception’. This implies that we think we have been awake all night when, in fact, we have slept on and off without realising it.
We all need eight hours of sleep. Most of us will need between seven and eight hours of sleep to feel refreshed in the morning. But there is considerable variation. Some people cope well with six hours, while others may need nine or even 10 hours of sleep. A very small minority, who may have some genetic predisposition, are very short sleepers, requiring only five-and-a-half hours of sleep.