The Doctor's notebook | Action Medical Research

Touching Lives - November 2006

The Doctor's notebook

What exactly is Seasonal Affective Disorder? Seasonal affective disorder, or SAD, is a type of depression that affects people during the autumn and winter months. It is attributed to a lack of daylight, which is why symptoms begin to appear as the days are drawing in. Some people only exhibit mild symptoms, known as ‘winter blues’, but for those who suffer the more severe effects, it can be seriously debilitating and disruptive to daily life.

Who is affected? SAD can affect anyone, but the most likely age of onset is between 18 and 30 years. It is thought that as many as one in 20 people are affected, with women three times more likely to suffer the condition than men. It is more common in northern countries because the further you go from the equator, the shorter the days become.

What are the symptoms? Researchers know that bright light makes a difference to brain chemistry, but as yet they do not know exactly how a lack of it can cause SAD. Symptoms tend to begin between September and November, and include:

 Sleep problems — oversleeping yet not feeling refreshed, or for some, not being able to sleep and awaking early.

 Overeating — craving sweet foods and carbohydrates, which can in turn lead to weight gain.

 Depression — feelings of hopelessness, despair, guilt, apathy and lethargy.

 Mood changes — suffering mood extremes, feelings of irritability, anxiety and an inability to handle stress.A desire to avoid social contact and loss of libido are also common.

A lot of sufferers also experience a weakened immune system during winter, finding themselves more vulnerable to illnesses and infections. However, by March or April, symptoms begin to ease as the days become longer and brighter.

What treatments are available? With lack of daylight being the root cause of SAD, the most effective treatment is exposure to artificial lighting. ‘Light therapy’ has proved effective in up to 85 per cent of cases, and involves specially designed light boxes fitted with particularly bright bulbs to imitate daylight. As little as 45 minutes a day in front of the light box can supply the brain with enough light to alleviate the symptoms of SAD and allow the continuation of a normal routine. Users do not need to look directly into the light — watching TV, reading the latest issue of Touching Lives, even tackling a Sudoku puzzle are all perfectly possible while sitting in front of the light box! So long as the light is not blocked out by sunglasses, this is one of the most effective SAD treatments there is.

Other treatment options include psychotherapy or counselling, and certain anti-depressants, which are most effective when combined with the light therapy. More detail on the condition can be found on the Seasonal Affective Disorder Association’s website, TL

Fact file

 SAD was first noted as long ago as 1845, but was not officially named until the early 1980s.

 It is estimated that three to five per cent of people suffer from SAD, with the incidences of ‘winter blues’ as high as 40 per cent.

 The unit measurement for illumination is ‘lux’. A standard household bulb emits between 250 and 500 lux, whereas a bright summer’s day can measure 100,000!

 Actor Johnny Briggs, who played Mike Baldwin in ‘Coronation Street’, and musician Rick Strom both suffer with SAD.

 A recent Canadian study found light therapy to be as effective as leading antidepressant drugs for SAD, with those undergoing light therapy responding more quickly to treatment. TL

Help us spread the word