What is Seasonal Affective disorder (SAD)?
Seasonal Affective disorder (SAD) is a mental health disorder that people experience at certain times of year. It is a form of depression, commonly known as winter depression as symptoms begin in autumn as the days begin to get shorter, and tend to persist until February. Most of our moods can be changed by the seasons; however individuals with SAD experience great effects on their mood, energy levels and motivation – hence leading to symptoms of depression.
- Approximately 1/15 people in the UK experience SAD during the winter months every year
- Normally, the most severe symptoms of SAD occur between December and February
- SAD is found in countries in the Northern and Southern hemispheres, but is very rare in
countries close to the equator
What causes it?
There is no exact cause known, however SAD is often linked to reduced sunlight in shorter autumn and winter days. The lack of sunlight could have an effect on brain chemicals such as melatonin and serotonin. Melatonin is a hormone that makes you feel sleepy, and people with SAD have been found to produce more of it during the winter months. Serotonin is a hormone that affects your mood, appetite and sleep – and a lack of sunlight may lead to a reduced production.
There is also some evidence that SAD runs in families, therefore SAD may have genetic factors involved. Other possible triggers may include a traumatic life event, physical illness, a change of diet/medication, and also the use of drugs and alcohol.
What are the symptoms?
The majority of individuals with SAD will feel depressed during the winter months. Symptoms will include: a persistent low mood, a loss of interest in normal activities, irritability, feelings of despair, low self-esteem, tearfulness, feeling stressed and anxious, reduced sex drive and becoming less sociable. People may also experience sleep problems, anxiety, panic attacks, eating problems and drug/alcohol misuse. Some people with SAD may also have manic periods where they feel excessively happy, energetic and sociable.
The symptoms of SAD can vary in severity and many people will not experience all symptoms. The symptoms may come and go suddenly, or they may appear gradually over time.
How is it diagnosed?
If an individual thinks they may have SAD, it is recommended that they make an appointment with a GP. The GP may carry out a psychological assessment, and ask about mood, lifestyle, eating and sleeping patterns, seasonal changes in thoughts and behaviours, personal history and family history. SAD can be difficult to diagnose, because there are many other types of depression that have similar symptoms. A diagnosis of SAD can usually be confirmed if: the depression occurs at a similar time each year; the periods of depression are followed by periods without depression and if symptoms are present during the same time of year for two or more years in a row.
How is it treated?
A range of treatments are available for SAD. Your GP will recommend the most suitable treatment programme for you.
The main treatments are:
lifestyle measures – including getting as much natural sunlight as possible, exercising regularly and managing your stress levels
light therapy – where a special lamp called a light box is used to simulate exposure to sunlight
talking therapies – such as cognitive behavioural therapy