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to information service page Mind booklet: Understanding seasonal affective disorder (SAD) |
'For years I suffered from depression. It started in the autumn, as the evenings drew in. By Christmas I would be so low I could barely get out of bed. I couldn't cope with organizing the celebrations, so we used to go to my mother-in-law's. One year I felt so bad that I went to bed on Christmas Eve and refused to move... That's what made me realize there was something seriously wrong.' Rita
Carter, 'Healthfront' in Daily Telegraph 22.10.94 It is light and its seasonal variation which cause these changes. As winter approaches, the hours of daylight become fewer, so that by December we often get up in the dark and return home from work or school in darkness. In addition to shorter daylight hours, the intensity of winter daylight is much lower. The light/dark cycle determines our sleeping and waking patterns. Until the widespread use of electric light, people used to wake and get up with the dawn light and sleep when it became dark. Nowadays we tend to manipulate the hours of light and darkness to suit our sophisticated lifestyle, and many night shift workers and jet-lagged air travellers suffer from disrupting their body clocks in this way. Light passes through the eye to the retina, and along a passage to the hypothalamus, a small but very important part of the brain which rules our body's main functions: sleep, appetite, sex drive, temperature, mood and activity. If insufficient light passes through the eye to stimulate these functions, they slow down and gradually stop, like a car which is running out of fuel. Most humans, like cars, slow down a little in winter when their fuel - light - is low. Some people seem to need a lot more fuel than others to keep them on the road, and these are the people who have seasonal affective disorder (SAD). What is SAD? SAD is a problem which affects 1-3 per cent of the UK population each year between October and April. A further 20 per cent experience a mild version of SAD called sub-syndromal SAD or winter blues, occurring mainly during December, January and February. SAD can be seriously disabling - some people cannot function in winter without continuous treatment. Many find it difficult to hold down a job in winter because of lethargy, sleepiness and poor concentration, and relationships often break up because the person with SAD becomes irritable, unloving and unlovable. Symptoms SAD symptoms happen regularly each winter, starting between September and November and continuing until March or April. Once someone has experienced three or more winters of symptoms, they may be diagnosed as suffering from SAD. Common SAD symptoms include a number of the following:
Most people with SAD have a lowered immune system during the winter, and are more likely to get continuous colds, infections and other illnesses. SAD symptoms go away in spring, either suddenly with a short period (several weeks) of hyperactivity, or gradually, depending on the amount of sunlight in the spring and early summer. In sub-syndromal SAD, symptoms such as tiredness, lethargy, sleeping and eating problems occur, but less severely and for a shorter period. Who gets SAD? SAD can begin at any age, but the most common age is 18-30. A survey of SAD Association members showed that SAD had started in 37 per cent of them before the age of 21, and 32 per cent between 22 and 35. No one really knows what triggers it. In the above-mentioned survey, 18 per cent said that events such as childbirth, hysterectomy or other hormonal upheavals seemed to have started it, 14 per cent thought it was triggered by a major loss or bereavement and 11 per cent by serious illness. At one time it was thought that four times as many women as men had SAD but more men now recognize their symptoms and seek treatment. Traditionally, men find it harder to admit to depressive symptoms and are more likely to try to find relief in alcohol and drugs than to go to the doctor. The ratio of SAD females to males seems more likely to be two to one. People get SAD throughout the northern and southern hemispheres, that is Europe, Scandinavia, most of North America and North Asia, and the southern parts of Australia and South America. It is extremely rare in those living within 30 degrees of the Equator, where daylight hours are long and extremely bright. People who have lived near the tropics for part of their lives and then emigrate to this country are more prone to develop SAD symptoms. People from different cultural backgrounds may manifest symptoms in different ways and may be misdiagnosed as suffering from schizophrenia or manic depression. What causes SAD? Scientists and doctors worldwide have been researching the cause of SAD since the early 1980s and there are several theories as to what causes it and where the problem lies. When light enters the eye it stimulates nerve impulses to travel to the hypothalamus which is the part of the brain that controls mood, appetite, sleep, temperature and sex drive. If there is not enough light entering the eye to stimulate the action of the nerve impulses, or there is a fault somewhere in the nerve pathway (probably at the suprachiasmatic nucleus - SCN) which slows down or prevents neural action, activity in the hypothalamus decreases and so do the functions it controls. The brain contains many millions of neurons, or nerve cells, and its messages have to travel from one neuron to the next to reach every part of the body. The messengers which carry the messages are called neurotransmitters - invisible substances which are very important in brain and body functioning. There are several neurotransmitters involved in SAD but the main one is serotonin. Levels of serotonin have been found to be lower in depressed people in winter, and it is thought that this neurotransmitter does not work properly in people with SAD. Drugs which increase the activity of serotonin - the SSRI drugs (antidepressants) -have proved successful in treating SAD and other types of depression. After reaching the hypothalamus, nerve impulses travel to a tiny organ behind it called the pineal gland. A hormone called melatonin is produced in this gland during the hours of darkness, and it is melatonin which makes us sleep in the dark. Melatonin production is suppressed by light, which explains why we wake up when we are exposed to bright light. People with SAD whose melatonin levels have been measured throughout the night, both in winter and in summer, have been found to produce much higher levels in the winter than those who do not experience SAD symptoms, but their summer levels are normal. When treated with bright light, melatonin levels drop to normal. However, suppressing melatonin does not cure the symptoms so this factor seems unlikely to be the sole cause of SAD. Another hypothesis is that the faulty SCN (suprachiasmatic nucleus) in SAD people slows the body's clock (circadian rhythm) and that this results in lethargy and depression. The delayed circadian rhythms may be reset with bright light in the morning to alleviate the symptoms. However, light treatment seems to work whatever time of day it is used, so this cannot be the only answer. Treatment for SAD Bright light is the most effective treatment for most people; it has been proved successful in 85 per cent of diagnosed cases. Light treatment means spending up to four hours per day (average 1-2 hours) exposed to very bright light, at least ten times the intensity of domestic lighting. Ordinary light bulbs and fittings are not strong enough. Equipment for light treatment comes in various forms; the most widely used is the light box. This is a box, ranging in size from a small tabletop TV-like box to a wall-mounted window type fixture, containing a number of bright light tubes covered by a screen. Other, more recently designed fixtures, include a light visor, a form of light treatment worn on the head which enables the user to move around; and a dawn simulator, a type of light alarm clock which wakes the user gently by gradually increasing the light level at the bedside. Light treatment has to be used daily in winter (and dull periods in summer), and should start in autumn when the first symptoms appear. The user sits one to three feet away from the light box, usually placed on a table, allowing the light to shine directly through their eyes. You can carry out normal activities while seated in front of the box, reading, working, or eating. You do not need to stare at the light, just glance at it from time to time. Light treatment starts to work in three or four days and the effect continues as long as it is used every day. Tinted lenses, or any device which blocks the light to the retina of the eye, must not be worn. Light treatment is perfectly safe; the UV is screened out so there is no danger of eye problems or skin cancer. Suntan lamps or boxes, which emit high levels of UV light, should not be used; only the specially designed SAD light boxes are recommended. Some light boxes are much brighter and can cut treatment time down to half an hour a day. Light boxes are not available on the NHS and have to be bought from specialist retailers; they are free of VAT and vary in price from £100-£400. You should try light treatment before buying a fixture; there are home trial schemes (see Useful organizations). Antidepressant drugs may be prescribed for people who experience severe SAD. The older antidepressant drugs such as amitriptyline, imipramine and dothiepin are not always useful for SAD as they increase the sleepiness and lethargy symptomatic of the condition. The newer SSRI drugs (Selective Serotonin Reuptake Inhibitors) such as paroxetine (Seroxat), sertraline (Lustral) and fluoxetine (Prozac) have been found to be more helpful and can be combined with light treatment. Going outdoors in natural daylight as much as possible, especially at midday and on bright days, can help, as can sitting near windows in light-coloured rooms when indoors. Psychotherapy, counselling or any therapy which helps the person with SAD to relax and cope with the problems caused by their condition are extremely useful. How can I help myself? The following are some useful tips: Recognize and accept that nature has decided that we cannot all cope as well in winter as we do in summer. We have to learn to simplify our life in winter, even if we cannot curl up in bed and sleep for six months. Decide the areas of your life which must carry on in winter, such as work, school, cooking meals, keeping the home going. Be ruthless about which tasks can be left until summer, especially major upheavals such as changing job, moving home, extra housework and decorating or repairs. It is a good idea to plan ahead for the winter. Buy Christmas presents in the summer, stock up the freezer and the store cupboard, give parties and see friends and relations when you want to, not when you feel you ought to (e.g. at Christmas). We need to keep active during the winter, but with routine unstressful activities that do not require maximum concentration and energy. Make the most of the available light. We know that being outdoors throughout the winter does not cure SAD as many farmers and outdoor workers have it, as well as those in gloomy factories and offices. One research study showed that a daily one hour walk around midday could be as helpful as light treatment for some mild cases. Decorate your home in light colours eg white, pale yellow, and aim to be near windows in shops, cafes and your workplace. Get some treatment and use it! Light treatment is marvellous and can transform your life, but it only works if you stick at it. Just as it takes three to four days for light to take effect, so the benefit can wear off if you do not use it for three to four days. Once you have got into the routine of using light (and it can be any time of day, except late evening; morning light seems to work best for 'owls' and evening light for 'larks') you can take occasional days off or go away for a long weekend, as long as you start again as soon as you return. If you can manage it, take your summer holiday in January or February! There is only one permanent cure for SAD, and that is to live within 30 degrees of the Equator. Few of us can do that, but we can take holidays, often at bargain prices, in sunny places such as southern Spain and the Canary Islands during the winter. Alternatively a ski resort which offers the extra brightness of light reflected off snow can be very beneficial. A word of warning! Some people with SAD have become much worse on returning to the UK gloom after very bright sunshine in places such as Africa. It seems that the contrast in light levels can do more harm than good for some people, so consult your doctor or the SAD Association (see Useful organizations) if you have any doubts. Finally, join the SAD Association for support and information. Knowing that you are not alone and that there is help available can make SAD much more bearable. How can family and friends help? It is not always easy to cope with a person with SAD. Sufferers are like two different people. a lively, cheerful and energetic person in the summer, and a sleepy, morose and irritable one in the winter. In summer, you will hardly be able to keep up with them; in winter, you will be unable to get much response. Most importantly accept that your friend or family member feels awful. Many people with SAD are still not taken seriously by family, friends and doctors which makes their suffering even greater. SAD can be a dreadful condition and many have been driven to suicide by it. Never imply that the person is lazy or not trying hard enough. They sleep because they have to; they have no control over their behaviour, and hostility or teasing only makes things worse. SAD is not funny; it is like being half dead, literally, for at least half of your life. Help your friend or family member organize things during the summer, especially treatment, as once their symptoms start they quickly become too apathetic to help themselves. As soon as you notice signs of lethargy, make sure the person uses their light or other treatment, and keep them at it! Do not let the person use their light treatment time to do chores for the family. If they need an hour's light before going to work or school, get another family member to prepare breakfast and get the children ready. Likewise when they return home after a day's work, light treatment must come first, so do not expect them to cook the evening meal immediately. Be sensitive to the person's needs and do not try to force them to do things they are really not up to (like inviting a houseful of relatives to stay at Christmas). You will suffer in the long run because they will be even more exhausted and stressed. Possibly the worst aspect of living with a person with SAD is their irritability and apparent unwillingness to give or accept love. This can be very upsetting, and is why so many relationships break up. The carer or partner often feels there is no point in continuing an apparently one-sided relationship. It is almost impossible for a person who has not experienced severe depression to imagine what it is like. The emotions of a depressed person are paralysed and they cannot feel happy, caring and loving in the normal way. They are not deliberately rejecting you although it seems like it; in fact, they are often desperate for love and care but are unable to accept them. Be gentle and patient, but insist they use their treatment and look forward to better times in the spring. Useful organizations SAD
Association British
Association for Counselling Further reading Winter
Blues Making Sense of Treatments and Drugs: Antidepressants (Mind 1998) £2.50 Mind
Complete Guide to Psychiatric Drugs (2nd ed.) Understanding Talking Treatments (Mind 1997) £1 Who Can I
Talk To? The User's Guide to Therapy and Counselling |
