Light Therapy & Seasonal Affective Disorder

Seasonal Affective Disorder (SAD) is a form of major depression that reoccurs at the same specific time every year.  Most commonly, it takes effect during the Autumn/Winter months (September until March) and is consequently known as the 'Winter Blues'. 

It is estimated that up to six percent of the general population suffer from SAD, with the disorder being more prevalent among females.

How do you know if you have SAD?

Symptoms of SAD can vary, but often include some or all of the following:

- increased sleep
- lack of energy
- overly inflated appetite

- irritability
- weight gain
- loss of short term memory
- loss of sex drive
- low self-esteem
- aches and pains
- inconsistent behaviours and indifference

As you may have already guessed, the onset of SAD is primarily caused by the lack of bright light during the darker months of winter.  When the eyes do not have certain levels of bright light each day, the brain chemistry is affected, which leads to many of the above symptoms.  It is not a psychosomatic illness and research suggests that it is more biological in its origin than other types of depression that can be brought on by social factors. 

How can SAD be treated?

The primary cause of SAD is a lack of bright light.  Although the lack of sunlight during the winter months is a major contributor, SAD can also be exacerbated by our lifestyles, as many Europeans now work up to 10 hours per day in artificially lit offices and rarely see daylight before or after work during these months.  To put the importance of sunlight into context - the sun emits up to 100,000 lux (the Metric measurement of light quantity), whereas artificial lights emit just 300-500 lux.  If this is our only source of light each day, it is easy to see how problems can occur. 

Thankfully, light therapy is extremely effective at treating SAD. Through the use of a light box or other bright light equipment for between 15 and 45 minutes each day the symptoms of SAD can quickly be alleviated.  The light that comes from a light box is the equivalent to the sun on a clear and bright Spring morning!  In addition to the standard light box, other equally effective devices include desk lamps, alarm clocks and visors - all of which can be used in different situations and to suit different lifestyles.

When and how to use light therapy

Light therapy should be used at a similar time each day until symptoms start to subside.  Once the individual feels an improvement, the session times can slowly be reduced or split into two sessions (A.M. and P.M.).

Should I consult my doctor?

We always suggest that it is wise to speak to a medical practitioner about any negative symptoms you may be experiencing.  The NHS Direct web site can be a good place to start, and support can be sought on a number of SAD support forums. 

If you have any questions or comments, please do not hesitate to contact us.