What is seasonal affective disorder (SAD)?
Seasonal affective disorder (SAD) is a form of depression that people experience at a particular time of year or during a particular season. Most of us are affected by the change in seasons – it is normal to feel more cheerful and energetic when the sun is shining and the days are longer, or to find that you eat more or sleep longer in winter. However, if you experience SAD, the change in seasons will have a much greater effect on your mood and energy levels, and lead to symptoms of depression that have a significant impact on your day-to-day life.
Most people experience SAD during the winter. Less commonly, some people find that they experience SAD in reverse – with depressive symptoms occurring in summer.
For years I suffered from depression. It started in the autumn, as the evenings drew in. By Christmas, I would be so low that I could barely get out of bed… One year, I felt so bad that I went to bed on Christmas Eve and refused to move.
You are more likely to experience SAD if you live in a country where there are significant changes to daylight, temperature and weather between seasons.
Because of this, SAD is more common in Scandinavia, Europe, North America, North Asia, and in southern parts of Australia and South America. It’s extremely rare to find people with symptoms of SAD living near the equator, where daylight hours are long and bright all year round. In northern Europe, it is estimated that about one in ten people experience some symptoms of SAD.
What are the common signs of SAD?
If you experience SAD symptoms for two or three years, you are likely to receive a diagnosis of SAD. There are many different symptoms of SAD, and you may experience some or all of the following:
- lack of energy for everyday tasks, such as studying or going to work
- concentration problems
- sleep problems
- depression – feeling sad, low, tearful, guilty, like you have let others or yourself down; sometimes hopeless and despairing, sometimes
- apathetic and feeling nothing
- anxiety – tenseness and inability to cope with everyday stresses;
- panic attacks
- mood changes – in some people, bursts of hyperactivity and
- cheerfulness (known as hypomania) in spring and autumn
- overeating – particularly craving carbohydrates and putting on weight
- being more prone to illness – some people with SAD may have a lowered immune system during the winter, and may be more likely to
- get colds, infections and other illnesses
- loss of interest in sex or physical contact
- social and relationship problems – irritability or not wanting to see people; difficult or abusive behaviour
- alcohol or drug abuse.
I first started feeling low in the winter months in my late 20s… Now, every autumn when the clocks change, I feel like I’m being buried alive. I want to hide away and hibernate until it’s all over.
In the UK, you may start to get SAD symptoms between September and November and they may continue until March, April or even May the following year. If you experience symptoms in reverse, they may begin around March and continue into the autumn. Symptoms tend to go away either suddenly (often with a short period of hyperactivity) or gradually, depending on the amount of sunlight in the spring and early summer.
For some people, symptoms are fairly mild and last for a shorter period, mainly during December, January and February, and are known as the ‘winter blues’, or sub-syndromal SAD. A small percentage of people have very severe symptoms and find it hard to carry out day-to-day tasks in winter without continuous treatment.