What is S.A.D.?
Seasonal Affective Disorder (known as S.A.D.) is a form of seasonal depression. It can range from extremely mild, just feeling a bit blue, to almost crippling intensity. Unlike other forms of depression this normally occurs during fall or winter and is usually relieved in the spring
Research is unclear about the average number of people affected, although it seems to be up to 4% of the population. Around 60% of people who already have a diagnosis of depression or bipolar disorder find themselves feeling worse during the fall and winter seasons.
It is most prevalent in northern climates, where there is less sunlight in the winter (up to 20% of all Scandinavians are thought to be affected, for example).
Women are four times more likely to be affected than men, wherever they are living.
What causes it?
No-one can say for sure yet. There are 3 current theories:
- Serotonin levels (which regulate mood) fall
- Melatonin is kept in higher levels (usually it peaks during the night and falls during the day)
- Your body cannot reset its circadian rhythms properly when when light levels fall too low
Whatever the cause, it is a very real problem for some people.