17 February 2006 - written by Alexander Whitehead for Bupa's health information team
Taking the substance melatonin does not seem to be effective in treating secondary sleep disorders and jet lag, according to a study published in the British Medical Journal this month.1
Researchers at the University of Alberta could find no evidence that melatonin can help people suffering from secondary sleep disorders or sleep disturbance associated with jet lag or shift work. They concluded that melatonin is safe to use for short periods, but that further research is needed to assess the safety of long-term use.1
Researchers looked at the effects of melatonin on 97 people who had secondary sleep disorders. These are sleep problems associated mainly with medical and neurological conditions.
Researchers also conducted trials on 427 people who had sleep disorders as a result of sleep restriction. Typically, people in this category were those whose sleep was affected by their lifestyle, such as jet lag from air travel or working irregular shift patterns.
A third round of trials was carried out on 651 people to assess whether there were any adverse effects in using melatonin for three months or less.
As with many clinical trials, placebo ('dummy') drugs were used as a way of ensuring more accurate results.1
Melatonin is a hormone found in the blood. It is secreted from the pineal gland. There are high levels of melatonin in the blood at night and lower levels during the day. Administering melatonin is thought to help control daily body rhythms and even alter the body's internal clock. It is one of the more popular over-the-counter products for treating sleep disorders. As with all complementary medicines, your GP is the best person to advise you on whether you should use it.
Around 770,000 people in the UK are affected by sleep disorders.2
Insomnia, often linked with anxiety and depression, is the most common disorder, affecting 10 to 15% of the population at any one time.3 Around 330,000 people suffer from obstructive sleep apnoea/hypopnoea syndrome (OSAHS), a condition where the narrowing or closing of the airways during sleep reduces blood oxygen levels, increases awakenings and causes excessive daytime drowsiness.2 Narcolepsy, a rare neurological condition most commonly found in teenagers and those in their early 20s, causes daytime drowsiness and causes people to fall asleep at any time. Around 28,000 people in the UK have the condition.
Anxiety, stress and depression often contribute to sleep problems. Alcohol and drug use also affect sleep. Other medical conditions can interrupt sleep patterns too. Pregnancy, menopause and the presence of young babies and children are other factors.
Obesity is a major factor in OSAHS. Extra fat, especially around the neck, increases closure of the airways during sleep when the muscles are relaxed.4
Insomnia increases with age and is common in the elderly.3 Periodic leg movement disorder (PLMD) is also more common in older people. This keeps people awake. PLMS affects 5% of 30 to 50-year-olds, 30% of people over 50 and 50% of people over 65.5
Yes. Children can experience nightmares, night terrors and sleep paralysis, all of which affect sleep. Sleepwalking is common, too. Most children grow out of experiencing these conditions.
Poor sleeping habits can increase the risk of hypertension, heart disease and stroke. They can also reduce libido, impair memory and cognitive functions, and lead to accidents at home or at work. More than 20% of motorway accidents in some parts of the UK are caused by sleepiness.6
There are many ways in which you can improve the quality of your sleep, such as:
People suffering from persistent sleep problems or excessive daytime sleepiness can see their GP or pharmacist for advice.
Bupa factsheet: Insomnia
Bupa factsheet: Snoring and sleep apnoea
Bupa factsheet: Sleep for school children
The Royal College of Psychiatrists
British Snoring and Sleep Apnoea Association
All pages were accessed on 15 February 2006.