SAD Info | Choosing a Light Box | 10,000 Lux | Full Spectrum
Info about Seasonal Affective Disorder (SAD)
UBC/VHHSC Mood Disorders Clinic - Many people feel mildly "depressed" during the winter, but some people have more severe bouts of feeling down all the time, low energy, problems with sleep and appetite, and reduced concentration to the point where they have difficulty functioning at work or in the home. We say that these people have a clinical depression, to distinguish it from everyday ups and downs. Seasonal affective disorder (affective is a psychiatric term for mood), or SAD, describes people who have these clinical depressions only during the autumn and winter seasons. During the spring and summer, they feel well and "normal". The common symptoms of SAD include:
Extreme fatigue and lack of energy
Increased need for sleep; sleeping much more than usual
Carbohydrate craving and increased appetite
How common is SAD?
Researchers believe that SAD results from the shorter day length in winter. Recent studies estimate that SAD is more common in northern countries because the winter day gets shorter as you go farther north. In Florida, less than 1% of the general population have SAD, while in Alaska as many as 10% of people may suffer from winter depression. In B.C., 2% to 5% of people probably have SAD. This means that up to 200,000 people in British Columbia may have difficulties in the winter due to significant clinical depression.
What treatments are available for SAD?
An exciting new research finding is that many patients with SAD improve with exposure to bright, artificial light, called light therapy, or phototherapy. As little as 30 minutes per day of sitting under a lightbox results in significant improvement in 60% to 80% of SAD patients. Side effects of light therapy are mild, although people with certain medical conditions or taking certain medications should avoid light therapy. Other treatments for depression, including antidepressant medications and counseling, may also be helpful for patients with SAD. People with milder symptoms of the "winter blahs" may be helped by simply spending more time outdoors and exercising regularly in the winter.
Why does light therapy work?
Choosing a Light Therapy Box
We don't know, exactly, but research shows that light has a biological effect on brain hormones and function. One theory is that people with SAD have a disturbance in the "biological clock" in the brain that regulates hormones, sleep and mood, so that this clock "runs slow" in the winter. The bright light may help to "reset the clock" and restore normal function. Other theories are that changes in brain chemical (neurotransmitter) function, particularly serotonin and dopa-mine, may be disturbed in SAD, and that these neurotransmitter imbalances are corrected by light therapy and/or anti-depressant medications. Still other scientists believe that patients with SAD have reduced retinal light sensitivity in the winter that is corrected by light therapy.
What is 10,000 Lux?
Lux is a unit of measure that indicates the brightness given by a light. The sun has a brightness of 93,000 lux while standard household lighting is about 1,100 lux. Most SAD light boxes generally deliver 10,000 lux. All of our light therapy boxes come with 10,000 Blue Lux Bulbs. These bulbs utilize Blue-Lux" technology combining a specific wave length in the Blue Spectrum with high intensity to produce a faster and stronger response to light than all other 10,000 lux and Full Spectrum Light Boxes. With typical light therapy products, a person has to sit within 2 feet of the source for light therapy for a period of 30 minutes to 2 hours. With the new Blue-Lux technology, we have incorporated it into the 10,000 lux bulbs so one simply has to be in the room to benefit. For instance, if you were in a 10 x 10 room youd receive the benefits simply from walking around the room. No longer does one need to sit directly in from of the light therapy source to receive the benefits.
What is Full Spectrum Lighting?
Full spectrum offers a truer color of light that is more like natural sunlight. A Full spectrum light box will emit a whiter or bluer light rather than yellow. Full-spectrum light generally has a brightness of around 2,500 lux. Full-spectrum lighting can be used throughout the day, for 10 to 12 hours at a time.
The full spectrum rating is designated by two factors: The first is Color Rendering Index (CRI), which designates the proportions of each color contained within the light. The second is Kelvin Heat Rating. Natural outdoor light has a CRI of 100 and a Kelvin rating of 7500 degrees Kelvin. Although there are no legal guidelines, 5000 degrees Kelvin and 90 CRI (or above) is considered full spectrum. In comparison, standard cool white fluorescent has a CRI of 68 while warm white fluorescent is 56 CRI. Standard incandescent bulbs have a 40 CRI.
To get the best of both worlds, try the Sun-A-Lux Combo Light Box with three light settings, letting you choose 10,000 lux brightness, full-spectrum (98C.R.I.) or both.
How far away should I sit from my light box?
The light is most effective when you are within an arm's length or approximately 2 feet of the Light Box. However it is still affective from across the room. Light is like a fireplace; the closer you are to it the more effect there is. It is recommended to never look directly into any type of light source. The light should enter the eyes but not be too harsh, so keeping the light box to the side has worked for many people.
How long will it be until I notice the effects of using my light box?
Most people notice improvement after one to three weeks of using the light box every day in the morning.