Seasonal Affective Disorder (SAD) is sometimes known as “winter depression” because the symptoms are more apparent and tend to be more severe at this time of the year. The symptoms often begin as the days start getting shorter in the autumn. They are most severe during December, January and February. However in most cases, the symptoms of SAD begin to improve when the days brighten and get longer in the spring before disappearing over the summer months.
Who can be affected by SAD?
It is thought that in the UK Seasonal Affective Disorder affects around 2 million people and more than 12 million people across Northern Europe.
The affects of Seasonal Affective Disorder don’t seem to be age specific. The symptoms are most likely to appear in someone aged between 18 and 30 years old but SAD can affect people of any age, even including children.
What are the Symptoms of SAD?
The symptoms of Seasonal Affective Disorder usually recur regularly each winter, starting late September into November and continuing all winter until March or April. When the weather is dark and gloomy, people tend to lack energy and feel less sociable. The amount of sunlight that you get can affect your mood, appetite, energy levels, and sex drive.
The symptoms of SAD may include any or all of the following conditions:
What causes SAD?
Despite numerous studies the exact cause of Seasonal Affective Disorder is not fully understood but it is thought to be linked to reduced exposure to sunlight during the shorter days of the year.
Sunlight has an affect on some of the brain’s chemicals and hormones although it is not clear exactly what this effect is. One theory is that light stimulates a part of the brain called the hypothalamus which controls mood, appetite and sleep, in turn affecting how you feel.
In people with SAD, a lack of sunlight and a problem with certain brain chemicals stops the hypothalamus working properly. The lack of light is thought to affect the production of the hormones melatonin (the hormone that makes you sleepy) and serotonin (the hormone that affects your mood), and disrupt the body’s circadian rhythm (otherwise known as the ‘body clock’ which regulates several biological processes over a 24-hour period).
Treating SAD with Light Therapy
For some people with Seasonal Affective Disorder using light therapy can help improve their mood considerably. Light Therapy involves sitting in front of or under a bright source of light to replace the missing sunshine.
Light Therapy lamps or light boxes come in a variety of designs, including desk lamps, floor standing lamps, and wall-mounted fixtures. They produce a very intense bright light – far greater than ordinary household lightbulbs can provide.
Light therapy is thought to work by simulating the sunlight that is missing during the darker winter months. This additional light encourages your brain to reduce the production of melatonin and increase the production of serotonin.
Altering the levels of melatonin and serotonin that are released into your body during the winter months can help to ease your symptoms of SAD. However, this is based on the assumption that the condition is caused by a lack of light and the effect that this has on the hormones that are released in your brain.
Before using a light therapy lamp or light box to treat SAD, check the manufacturer’s information and instructions regarding whether the product is suitable for treating SAD, the light intensity you should be using, and how long you need to sit in front of the light to receive sufficient ‘dose’ of light to be beneficial. Make sure that you choose one that has been produced by a fully certified manufacturer and is medically proven to treat SAD.
Very bright light may not be suitable if you have an eye problem or your eyes are particularly sensitive to light, you are taking certain types of medication such as antidepressants, or if you have epilepsy. If you unsure about the suitability of a particular product please speak to your Doctor.