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Insomnia is not simply a disorder of sleep – it also affects wakefulness and can lead to irritability, fatigue and long-term health problems.

 

An estimated 10-40 per cent of the general population suffers from insomnia, with prevalence varying widely depending on the definition used.

Two of the main diagnostic systems used are the International Classification of Sleep Disorders (ICSD, republished last year) and the Diagnostic and Statistical Manual of Mental Disorders (DSMIV).

In both of these systems insomnia is defined in terms of problems getting to sleep, staying asleep or waking up too early, and these problems must happen at least three times a week and for at least three months, says Kevin Morgan, professor of psychology and director of the clinical sleep research unit at Loughborough University.

“Two additional important aspects are adequate opportunity for getting to sleep and association with impaired social or occupational functioning,” he says. Insomnia can be categorised as acute or chronic, depending on the period of time over which symptoms are experienced, or according to the symptoms themselves.

Sleep maintenance problems, for example, are the most prevalent and are reported by 50-70 per cent of people who suffer from insomnia. Traditionally, the condition has been classified as primary or secondary but these labels have now been discredited. “The concept of secondary insomnia, that another cause came first, was totally rejected in the mid-2000s,” says Professor Morgan.

“It was always a clinical assumption – there was no evidence to support it and the notion was never demonstrated.” In cases of so-called ‘secondary insomnia’, either the insomnia or the purported cause could be treated, and resolve, independently of the other, he notes.

“A person might have cancer, a sports injury, or arthritis, as well as insomnia. Yet when the insomnia is independently treated, it can recover independently of the other condition. And if you independently treat the symptoms of the condition, you can still have insomnia. It is independent. Co-morbidity is not causal or directional.”

So, if insomnia is not caused by other conditions, as was frequently thought, does it cause medical and/or psychiatric problems? The answer appears to be a resounding – ‘yes’.

There may be a loss of about six years off a person’s life when they do regular changing shift patterns

Co-morbidities

Insomnia is associated with a number of co-morbidities. The association between insomnia and cardiovascular risk is fairly well-established. Insomnia increases the risk for both hypertension and myocardial infarction.

There is also a link between insomnia and the development of type 2 diabetes. For those individuals who have insomnia as well as type 2 diabetes, it has been suggested that their diabetes is more difficult to control than that of those who do not suffer from insomnia. Implicated mechanisms include weight gain, activation of the stress system and inflammation.

There is also a reported link between insomnia and psychiatric disorders. Insomnia is a strong predictor for depression and is also thought to increase the risk for anxiety and suicide. An association with alcohol dependence has also been reported in the literature.

Insomnia can, by its very definition, impact on day-to-day functioning with difficulties concentrating, memory problems, and issues of focusing. Such functional consequences can have an impact on livelihood too, resulting in reduced productivity and increased time off work. Finally, reduced sleep increases pain sensitivity, that can lead to a difficult-to-break cycle in which pain causes insomnia, which, in turn, exacerbates the pain.

Lynne Haygarth, a mental health specialist and former chief pharmacist, says it is important to consider the socio-economic impact of lack of sleep, which can include chronic physical health problems, as well as accidents.

“There have been large studies looking at the impact of lack of sleep on shift workers. These studies examine the predisposition to diabetes and the fact that, in reality, there may be a loss of about six years off a person’s life when they do regular changing shift patterns.” Professor Morgan points out that chronic insomnia is a strong independent risk factor for depression.

“You are about five times more likely to have depression if you have insomnia. It will also cause accidents and emotional lability. The ability to regulate mood disappears. You get snappier and become intolerant. People with insomnia do not perform at their best.

“In the US there is some evidence that insomnia may lead to obesity, but the jury is out on that one. It is safe to say that insomnia may predispose to hypertension, because if you sleep less, you eat more.”

 

Identifying insomnia

A number of objectively measured factors can help identify those who suffer from insomnia. These include polysomnography to objectively measure sleep time (although lack of objectively short sleep duration does not in itself preclude insomnia), increased beta frequency waves in the EEG, increased cortisol levels, elevated heart rate/sympathetic activation, higher systolic blood pressure, high blood glucose, increased metabolic rate, inflammatory markers, immune system deficits, ghrelin/leptin assays, and levels of GABA in the brain.

The association between insomnia and inflammation is interesting. Studies show different secretory patterns of pro-inflammatory cytokines such as IL-6 and TNF-alpha in people with insomnia. One study examining treatment of rheumatoid arthritis in patients with poor sleep with anti-TNF-alpha medications reported a significant decrease in wake-time during sleep and increased efficiency of sleep after just two months of therapy.

Reduced sleep has been shown to have a negative impact on the immune system. Research has demonstrated significant reductions in a number of immune cell populations including CD3+, CD4+ and CD8+ T cells and reduced NK-cell responses in people with insomnia.

Electronic devices

The role of electronic gadgets in the development of insomnia has been a recent subject of debate. Iqbal Mohammed, community pharmacist and teacher practitioner at the University of Huddersfield, believes that the use of electronic devices is implicated in insomnia, with melatonin the link between the two. “Melatonin plays a significant role in the regulation of our sleep patterns” he explains. “The detection of light inhibits melatonin and causes wakefulness, which in due course will eventually disturb sleep.

“Melatonin levels also decrease with age. This may be apparent in newborn babies who seem to everlastingly sleep and the elderly having problems with the amount of sleep they can get. The majority of insomnia cases that I come across in my pharmacy are elderly people waking up in the middle of the night.”

“We all have an opinion on why we sleep better on certain days than others and, of course, there are many factors that affect our sleep, but it has been found that we sleep 20 per cent less than people from the early twentieth century. Is this a coincidence? Do we have additional stresses these days? In my personal opinion, it comes down to a number of factors but one in particular – technology.”

Professor Morgan is not so sure. “The counter-argument,” he says, ”is that we have never slept in more comfortable beds. We have never been better nourished. We have never had it so good when it comes to sleep. The argument that sleep is being challenged by a mobile phone does not hold up.”

Treatment options

Iqbal Mohammed offers the following advice for anybody suffering from insomnia:

• Get into a routine and try to go to sleep at the same time each night
• Instead of watching television or using your laptop, try to read a book. This has been shown to increase the likelihood of sleep
• Turn your phone to silent and place it upside down. Do not worry if you have your alarm on – it will still buzz in the morning
• • Try to sleep in complete darkness or as near to it as possible. If there is light entering the room, this will reduce melatonin secretion
• Music has been shown to aid sleep, so if you have a relaxing piece of music, play it
• Have a shower or a bath to help you relax
• If you are cold, sleep with a hot water bottle if you are waking up in the middle of the night. It is most likely that your body temperature has dropped and not the temperature in your bedroom.

Behaviours that are thought to help promote sleep are generally termed ‘sleep hygiene’. Examples include:

• Do not ‘try’ to sleep – the more you worry, the less you will sleep
• Avoid stimulants such as caffeine or nicotine
• Limit alcohol intake
• Maintain a regular sleep schedule seven nights a week
• Avoid naps
• Get regular exercise, at least six hours before sleep
• Keep the bedroom dark and quiet.

 

Self-help programmes

“When it comes to the management of insomnia, pharmacists should be on top of at least one self-help programme,” says Professor Morgan. “And they should tell patients that if it doesn’t work, they would strongly recommend talking to a GP.” The two evidence-based treatments that are approved for insomnia are cognitive behavioural therapy for insomnia (CBT-I) and hypnotic drugs.

“The first-line treatment for insomnia is CBT-I, which is recommended by NICE and by the Royal College of Psychiatrists.” Unfortunately, lack of training and resources for CBT-I can limit its use in day-to-day practice. The objectives of CBT-I are to address maladaptive behaviours, thoughts and beliefs surrounding sleep that can exacerbate, or perpetuate, insomnia.

Targets may include sleep education, stimulus control techniques, cognitive therapy and, sometimes, relaxation training. Behavioural therapies are most important in older individuals, given the increased risk of medication adverse effects among this population.

Hypnotic drugs

“Hypnotic drugs are extremely effective in the short-term, and extremely ineffective in the long-term,” says Professor Morgan. “In the short-term, hypnotic drugs reduce the time it takes to get to sleep, reduce the incidents of waking up during the night, and result in patients feeling better slept. Prescribed according to licence, no approved hypnotic drug should be given for longer than four weeks; some for no longer than three weeks.”

“In the long-term, tolerance takes place after a year. The sleep profile with hypnotic drugs at this time is the same as that for untreated insomnia. Also there’s an addiction problem.”

“Unfortunately, most insomnia is chronic so there is a mismatch between the time range for which these drugs are effective and the typical insomnia that presents in primary care.” Lynne Haygarth agrees that hypnotics are only valuable if they are used appropriately.

“The ‘Z drugs’ were prescribed widely and inappropriately with no recognition of their dependence and abuse potential. Drugs affecting GABA are likely to be abused, which is a long-term problem with benzodiazepines, in particular diazepam and temazepam.” Despite the fact that benzodiazepine receptor agonist drugs have garnered the most evidence with respect to their efficacy in insomnia, concerns persist surrounding the risk/benefit ratio.

NICE’s Clinical Knowledge Summaries highlight the fact that, for the elderly in particular, the risks of cognitive impairment and falls may outweigh their benefits. If an hypnotic is prescribed NICE advises that:

• The lowest effective dose be used for the shortest possible period
• The patient is informed that further prescriptions will not usually be given
• Further prescriptions should not be issued without seeing the patient again
• Further prescriptions should not be issued if the first hypnotic has not been effective
• If adverse effects experienced are directly attributable to the hypnotic, another hypnotic should be considered.

Insomnia is basically a psychiatric issue and drugs will not get to the root of the problem, says Professor Morgan. “Hypnotic drugs don’t treat the causes of insomnia – insomnia is not caused by a benzodiazepine deficiency.”