Seasonal Affective Disorder (SAD)

Seasonal Affective Disorder (often called SAD) is the name given to a type of depression. It is also known as winter depression. The symptoms of depression start in the autumn or winter and get better in the spring. It is very common, affecting an estimated half a million people per year. For doctors to make this diagnosis, this pattern has to happen in two consecutive years

WHAT CAUSES SEASONAL AFFECTIVE DISORDER?
What causes SAD is unclear but it maybe a shortening of daylight hours and a lack of sunlight in winter. This causes a chemical imbalance within parts of the brain called the hypothalamus and the pineal gland. The result is an abnormality of the brain hormones called melatonin and serotonin; the outcome of which is that they are not at usual levels. Melatonin is produced in the pineal gland in the hours of darkness and causes sleepiness. In people with SAD, bright light reduces the amount of melatonin and increases the amount of serotonin

WHAT ARE THE SYMPTOMS?
The following can occur

• Low mood
• Anxiety/irritability
• Oversleeping/tiredness
• Overeating with craving for carbohydrates/sweet foods
• Lethargy
• Difficulty coping at home and at work
• Avoidance of social contact
• Weakened immune system with more risk of infection
  

These symptoms start in the autumn, worsen as winter progresses and improve with the approach of spring

MEDICATION AS A TREATMENT FOR SAD
Antidepressant medication can be used to treat Seasonal Affective Disorder. However light therapy can be used on its own or in combination with antidepressant medication

LIGHT THERAPY AS A TREATMENT FOR SAD
This involves sitting in front of a "light box" for a period of time. The light box exposes you to intense levels of light usually between 5-20 times brighter than a well lit office. A light box is a specific piece of equipment containing a set of florescent light bulbs with a screen. You don't have to wear glasses or get undressed. You don't look directly into the light. You can read, write or do any other activity whilst sitting in front of it

Where can I get light treatment?
Unfortunately, light boxes are not available on the NHS. They may be bought from a company that specialises in light boxes. Several companies offer a free home trial service. Your GP may be able to advise you or you can contact the Seasonal Affective Disorder Association (contact details at the end of this leaflet)

How often should light therapy be used?
Light treatment should be used daily in winter starting in autumn when the first symptoms appear. Treatment is usually effective within 3-4 days but may take several weeks. The length of treatment depends on the intensity of the light and the severity of your symptoms. Usually 45-60 minutes each day is beneficial. It is best used in the morning or during the day - not late at night since it may keep you awake

Are there different types of light box?
Yes. They vary in size, intensity of light and of course cost. Some are portable and some sit easily on a desk so you can work at the same time. Some companies sell a "light visor" which is a lightweight cap containing the light. This has not been fully tested in the UK but does allow you to walk around whilst getting the light treatment at the same time. There is also a "Dawn Stimulator". This is a bedside lamp which is timed to produce a graded dawn which wakes you when it reaches full intensity. This is unlikely to produce full light treatment but may be useful for mild symptoms

Are there any side effects?
Some people have complained of headache, eyestrain, nausea and hyperactivity. These complaints are fairly uncommon. They usually last only a little while. They do not usually stop people continuing to use the light box

OTHER USEFUL HINTS
If you suffer from Seasonal Affective Disorder it is important to:

• Get plenty of sleep and relaxation
• Eat a healthy diet
• Get as much natural daylight (especially mid day and on bright days)
• Exercise regularly

HELP AND SUPPORT
You may wish to consider contacting:

• For Information about Seasonal Affective Disorder and how to obtain and use light boxes contact: Seasonal Affective Disorder Association, PO Box 989, Steyning, West Sussex BN44 3HR. Tel: 01903 814942 www.sada.org.uk
• www.mentalhealthleeds.info (Leeds Mental Health Directory on-line) Includes database of more than 600 organisations working on mental health in Leeds, and direct links to many other useful websites
• NHS Choices - 0845 46 47 (24 hours). Free information service on all aspects of health problems, NHS services and other local services www.nhs.uk

Source: Leeds Mental Health Trust and Leeds Primary Care Trusts
The original version of this leaflet was written by Ardsley Community Mental Health Team, East Ardsley Health Centre, Wakefield WF3 2DN

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Last revision: January 2012