Seasonal Affective Disorder (SAD)
This News Article is for people that have Seasonal Affective (or mood) Disorder (SAD), or who would like information about it.
SAD is a type of depression with a seasonal pattern, occurring most commonly in the winter months.
Many people have changes in their sleep patterns, energy levels and mood in the autumn and winter. Indeed, many people can feel "low" during long periods of grey days the winter. However, this unhappiness can develop into SAD. Mild forms of SAD are commonly referred to as "winter blues" but you can have a more severe form and become unable to function in the winter without treatment.
About one in 100 people in the UK get SAD, most commonly between the ages of 18 and 30, although it can develop at any age. More women are affected than men.
Symptoms of SAD
If you have SAD your symptoms often get worse in the autumn and winter when the days are shorter, and clear up in spring and summer. You are more likely to get SAD the further away you live from the equator as daylight hours become fewer. You may get SAD in the summer months but this is much less common.
The symptoms of SAD can vary from person to person, and are similar to those that develop in other types of depression. The common symptoms include:
- A low mood for most of the day
- Needing more sleep and sleeping more than usual
- Eating more than usual, especially craving carbohydrates, leading too weight gain
- Loss of interest in sex (libido)
If you have these symptoms during the winter months, you should see your GP.
Causes of SAD
The exact cause of SAD isn't fully understood at present, although there are theories.
SAD may be related to changes in the amount of daylight during the autumn and winter. One theory is that light stimulates a part of the brain called the hypothalamus, which controls mood, appetite and sleep. In people with SAD, lack of light and a problem with certain brain chemicals and hormones prevents the hypothalamus from working properly.
- A chemical called serotonin has a role in "lifting" the mood. It's thought that people with SAD may have abnormally low levels of chemicals such as serotonin in winter.
- A hormone called melatonin slows down the body clock, and affects sleeping and mood patterns. People with SAD may respond to a decrease in light by secreting more melatonin than people without SAD. However, medicines designed to suppress the secretion of melatonin don't stop the symptoms of SAD, so this isn't the only factor.
If you have a close relative with SAD, you may be more likely to develop it.
Diagnosis of SAD
Your GP is a good first point of contact. He or she will ask about your day-to-day life and symptoms. One about of the "winter blues" doesn't automatically mean you have SAD. But, if you have regular symptoms over three or more consecutive years in autumn/winter which clear in the spring, the diagnosis may be SAD.
Your GP may also want to rule out other forms of depression.
Treatment of SAD
There are a number of steps you can take to reduce the effects of SAD. Wherever possible, you should:
Try to find time each day to get outside
Sit near windows when you are inside
Take regular, moderate exercise
Eat a well-balanced diet
Decorate your home in light colours
Leave any major projects until summer and plan ahead for the winter
Not put yourself under stress and learn relaxation techniques
Your GP may recommend antidepressant medication normally used for other forms of depression.
If your GP prescribes antidepressants, you may only need to take them during the winter season, instead of all year round.
Light therapy (also called phototherapy)
Research has shown that exposure to bright, artificial light can improve symptoms in about eight in 10 people with SAD. The aim is to provide bright summer light to stimulate a change in the levels of chemicals and hormones which affect the mood (see causes).
- Bright light is delivered by devices including:
- A specially made light box - these range in size
- Light caps or visors that are worn on the head like a baseball hat
- Dawn simulators - these are in the form of a bedside light, connected to an alarm clock that mimics a sunrise and wakes the user gradually
The light is at least 10 times stronger than that from normal light bulbs. It's very similar to natural daylight and it won't harm your eyes, unlike strong Ultraviolet (UV) light. You should never user homemade lights units, such as tanning lights or beds for light therapy. The light given off by these units is high in UV rays and can harm your skin and eyes.
The recommended exposure time to bright light depends on the power of the light source. An effective dose is 5,000 lux per day, given as 2,500 lux for two hours or 10,000 lux for 30 minutes each day, during the autumn and winter months (where lux is a measure of the intensity of light).
Light box treatment can be done in your own home or office. Light boxes aren't available on the NHS but you can buy or hire one - contact the SAD Association for a list of suppliers.
Most people notice an improvement in symptoms within three to four days. You should continue to have light therapy every day until spring - when there are more daylight hours.
Light therapy has few side-effects but they include headaches, irritability, and in rare cases, it can make you feel sick.
You should get advice from your GP before starting light therapy.
Talking therapies are also available, which include cognitive behavioral therapy (CBT). CBT is a short-term psychological treatment that helps to change the way you think, feel and behave. CBT is a combination of two types of therapy:
- Cognitive therapy, which helps with thinking processes such as unwanted thoughts, attitudes, and beliefs (called cognitive processes)
- Behavioral therapy, which focuses on behavior in response to those thoughts
Help and support
Tell your family and friends about the condition and its effects so that they are to help support you. You may find it helpful to join a support group. Knowing that you are not alone and that help is available can be a great comfort.