SAD: what is it?

I suffer from "winter blues" lethargy caused by lack of sunlight. Although I am pulling out of it now that spring is here, I am aware that it is getting worse each year, despite global warming and spending three days a week outside. Last summer, I questioned my GP, who said that light treatment does not work that well. He suggested a course of mild antidepressants over the winter months. I do not rate myself as depressed, so it does not seem that logical to take antidepressants. What treatments might help?

Dr Fred Kavalier answers your health question:

SAD, which stands for seasonal affective disorder, is the fancy medical name for this. The theory is that the change of seasons, or lack of sunlight, somehow affect the brain and cause at least some of the symptoms of depression. When the light returns again in the spring, the symptoms disappear. A small number of people seem to have the problem in reverse - they get worse in the summer and better in the winter.I think you are wrong to think it is not a form of depression. Women are more prone to SAD than men, and it seems to get commoner with increasing age. The most usual symptoms of winter depression are increased sleep, increased appetite, weight gain, irritability and problems with relationships (especially feelings of rejection). There is some evidence that light therapy helps, but it is not effective for everyone with SAD. You have to sit in front of a specially designed light box every day for 30-90 minutes. People who respond to this treatment often begin to feel better within days. I don't think a winter course of antidepressants is a bad idea, but it depends on the symptoms you get and how severe they are. As with other forms of depression, another treatment option is cognitive behaviour therapy.

Please mail your questions for Dr Fred to health@independent.co.uk. He regrets that he is unable to respond personally to questions.