December and January are the darkest months of the year in the UK. For some this heralds the start of a bout of severe depression known as Seasonal Affective Disorder (or SAD). Seasonal Affective Disorder is most probably related to the amount of daylight. In countries away from the equator it tends to increase in the darker months. For example, in the UK Seasonal Affective Disorder is worst in December January and February. Seasonal Affective Disorder, however, is rare in countries near the equator with their long, consistently bright days.
The NHS estimates that about one in fifteen adults in the UK (about 7%) suffer from SAD between the months of September and April. SAD is four times more common in women than men.
Studies suggest a further 10% to 20% may have the milder form of SAD often referred to as the ‘Winter Blues’ .Whilst Winter Blues can be tackled by self-help, see our page on beating the winter blues, SAD disorder often requires medical intervention.
The key to success with stopping SAD disorder becoming debilitating is to diagnose and then treat it early.
What are the symptoms of Seasonal Affective Disorder?
Not everyone with Seasonal Affective Disorder has the same symptoms. The common symptoms of SAD include the following:
- Sleep Problems; usually oversleeping and difficulty staying awake
- Poor Sleep quality
- Loss of energy
- Increased appetite, especially a craving for sweet or starchy foods
- Weight gain, as a result of the above
- Depression (apathy)
- Mood changes with general irritability
- Difficulty concentrating
- Increased sensitivity to social rejection
- Avoidance of social situations—not wanting to go out
- Decreased sex drive
- Weakened immune system – more colds and flu
What is the cause of SAD?
The exact cause of SAD remains unknown. However, it has a genetic component (it runs in the family) and is often associated with Bipolar Disorder.
Scientists believe SAD involves problems in the regulation of the hormone melatonin, which gives us the desire to sleep. Here, in the darker winter months SAD sufferers have an over production of Melatonin. This affects the body clock or circadian rhythm and leaves them feeling lethargic and sleepier.
It is also thought that SAD involves a reduction in Serotonin activity in the brain during the darker winter months. Serotonin is one of our key neurotransmitters. Reduced Serotonin causes problems with mood, appetite and sleep. It is also linked to feelings of depression.
The combination of increased melatonin and decreased Serotonin then affects our body clock or circadian rhythm. This rhythm is tuned into the light-dark changes, which naturally occur throughout the year. It would seem that for SAD disorder sufferers the impact of changes of day length in the winter are timed differently. This then makes it harder for their bodies to adjust.
The darker, gloomier winter days may also directly disrupt the body clock as the distinction between day and night is less clear.
Finally, SAD sufferers have reduced production of Vitamin D in the darker months. Vitamin D is created in the skin by ultraviolet B (UVB) sunlight. Low levels of Vitamin D are associated with low mood and depression.
See your GP if you think you have SAD
If you think you suffer from SAD always go to see your GP rather than try to treat it yourself. Your GP will then carry out an assessment. This will normally involve asking you about any seasonal changes you have in your behaviour and thoughts. It will also cover your general mood, lifestyle and eating habits.
Treatment for SAD
Light therapy is one treatment which is often used to help SAD sufferers. It is highly effective for those whose SAD is light dependent. Typically, this involves sitting in front of a light box for about 30 minutes a day. Getting outside in the day, opening your curtains and blinds would also support getting more sunlight. A Dawn simulator would also be a great replacement for the alarm on your phone too.
Behavioural therapy can also be offered by your GP, often alongside light therapy. In particular it will be added if light therapy isn’t working.
Improving your lifestyle will have a significant impact especially when your Seasonal Affective Disorder is multi-factoral. This includes healthier eating and increasing your exercise. Exercise is a great anti-depressant as it increases endorphins. It also burns off Adrenalin and helps to manage stress levels. Getting out and socialising more will also help raise your mood.
Antidepressants are sometimes prescribed such as selective serotonin re-uptake inhibitors (SSRIs).