When daylight hours get shorter and temperatures begin to drop, some people start to experience mild depression caused by a clinical condition known as Seasonal Affective Disorder. We explain what the signs are and how it can be treated.

Symptoms include excessive tiredeness and mood swings

During this time of year, when daylight hours get shorter and temperatures begin to drop, many of us start to feel less energetic and long to retreat into a warm, cocoon-like sanctuary until spring arrives. For some of us, especially those originally from warmer climates, these feelings take on a stronger form and the shorter days that characterise the approach of winter causes a mild form of depression. Now officially recognised as a clinical condition, Seasonal Affective Disorder (SAD), is thought to be caused by sunlight deprivation. SAD manifests itself in the following ways: Oversleeping, but not feeling refreshed - being tired during the day and needing an afternoon nap
Overeating - craving carbohydrate-rich or starchy foods, often leading to weight gain
Mood swings - feelings of despair, guilt, anxiety, inexplicable irritability, frustration with an inability to complete normal daily tasks
Social problems or avoidance - family problems or arguments, avoiding company and withdrawing from social situations, loss of libido
Lethargy - too tired to cope with daily life As a secondary effect, a weakened immune system will leave the sufferer vulnerable to other general infections. The symptoms of SAD will sometimes affect long-term lifestyle. Dr Peter Paul Mersch, of the Department of Biological Psychiatry at the University Hospital Groningen, in the Netherlands, co-authored a paper on the subject in 1999. He revealed that those suffering from the effects of SAD are more often unemployed or absent for long periods of time than people not reporting the symptoms. The investigation has shown that reduced exposure to sunlight results in a biochemical imbalance in the hypothalamus (part of the brain) in affected patients. The hypothalamus controls body functions such as sleep, appetite, temperature, sex drive, mood and activity. An insufficiency of light passing to this part of the brain creates a slow-down in these functions.

Women are four times more likely to suffer SAD than men, under-40s most affected

SAD usually occurs between the months of September and April, with many sufferers experiencing exaggerated feelings of buoyancy and happiness during the spring and summer. It affects two percent of the population of northern Europe, with up to 10 percent experiencing mild symptoms. Women are four times more likely to suffer with SAD than men and it is most common in the 24 - 40 age group. It is also becoming increasingly evident that some respondents are showing signs of "summer SAD". The above study revealed a low prevalence of 0.1 percent. However, many recent papers still do not report summer SAD figures separated out from the overall results. The conventional treatment for SAD is light therapy. The sufferer spends time in front of a desktop light box fitted with full-spectrum fluorescent bulbs. For most patients, 30 minutes per day will have some beneficial effects, though headaches and eyestrain are possible side effects. Non-sedative antidepressant drugs are also sometimes effective, if used in conjunction with light therapy. "Basically, the disorder is merely controlled by light therapy and patients need treatment every year," Dr Mersch said. "However, follow-up studies show that on the long run the disorder has disappeared in many patients or has turned in a "non-seasonal" depression." Simple homegrown measures include: Streamline your life during the winter months: don't move house, don't change jobs nor take on extra home or work responsibilities
Maximise your exposure to available daylight: sit near windows at home, work, in cafes and restaurants
Try and take a holiday to a brighter climate in January or February: bargain winter breaks to southern Europe or skiing holidays can alleviate those post-Christmas blues Most importantly - recognise the symptoms and consult your doctor. © Expatica Communications First published October 2002