Seasonal affective disorder (SAD) is a type of depression that you experience during particular seasons or times of the year. Depression is a low mood that lasts for a long time and affects your everyday life. If you have SAD, you'll experience depression during some seasons in particular, or because of certain types of weather. It's common to be affected by changing seasons and weather or to have times of the year when you feel more or less comfortable.
But if your feelings are interfering with your day-to-day life, it could be an indication that you have depression – and if they keep coming back at the same time of year, doctors might call this seasonal affective disorder or “seasonal depression.”
If you have SAD, you might experience some of the signs and symptoms below. But it's different for different people, and can alter season to season, so you might also have other kinds of feelings which aren't listed here:
lack of energy
finding it hard to concentrate
not wanting to see people
sleep problems, such as sleeping more or less than usual, difficulty waking up, or difficulty falling or staying asleep
feeling sad, low, tearful, guilty, or hopeless
changes in your appetite, for example, feeling more hungry or wanting more snacks
being more prone to physical health problems, such as colds, infections, or other illnesses
losing interest in sex or physical contact
symptoms of depression
The exact causes of SAD aren't clear. It seems that the things we know can cause depression, in general, can lead to SAD, and research has also suggested that there are a few things that could contribute to the development of SAD in particular. Depression can vary a lot between different people and you might have SAD due to a combination of factors, or there might not seem to be any specific reason.
Some causes are:
The effects of light
Disrupted body clock
High melatonin levels
Weather and temperatures
Whether or not your depression seems to be seasonal, it's ok to ask for help at any time. The first step is usually to visit your GP and if you're given a diagnosis of SAD, it will be based on whether your symptoms repeatedly follow a seasonal pattern, usually, for two or more years – it doesn't depend on the specific season or time of year when you're affected.
There are many other methods as well to treat SAD. Some include but are not limited to: