1. Why do I feel so down and depressed during the winter?
2. What is Seasonal Affective Disorder (SAD)?
3. What causes SAD?
4. What are the symptoms of SAD?
5. What are the problems with indoor lighting?
6. How can full-spectrum lighting help me?
7. Aren't UV rays unhealthy?
8. What is this I've heard about light and PMS?
9. Are the lights medically approved? Is a prescription needed?
10. Why does light therapy work? 
11. Will full-spectrum lighting cost me more or less in the long run?

Why do I feel so down and depressed during the winter?

In fact, 25% of the population in Canada have these symptoms. Nearly 350,000 people in the British Columbia lower mainland suffer from a newly named syndrome: Seasonal Affective Disorder (S.A.D.).

Recent studies at UBC in Vancouver and the Presbyterian Medical Centre in New York indicate that people living in the northern part of the hemisphere suffer from seasonal mood disorders more than others who live in southern areas where sunlight is more prevalent in winter. Particularly in British Columbia, where they experience long periods of dark, dismal, rainy days, there is a higher incidence of S.A.D. than in other parts of Canada.

Reference: SEASONAL AFFECTED DISORDER AND SYMPTOMS OF DEPRESSION: Light Boxes for the Winter Blues, "Why do I feel so down and depressed this time of the year?" by Tom MacKay

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What is Seasonal Affective Disorder (SAD)?

Seasonal affective disorder (or SAD) is a clinically diagnosed condition in which the lack of sunlight in winter literally makes people ill. SAD affects 10 to 12 million people in the United States and millions more around the world. 

SAD is also observed in people with cataracts, who have less natural light entering the eye and contacting the retina. In addition, for every person suffering from SAD, two or three more suffer from a less severe form of the "winter blues." And now, researchers are finding connections between a lack of sunlight and seemingly unrelated conditions like PMS, insomnia, and obesity. 

The fact is that no matter where you live, unless you spend two or more daylight hours outside every day, you are likely to suffer some of the symptoms of light deficiency, or malillumination syndrome (MIS). 

Reference: Health Sciences Institute, November, 1998 issue 

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What causes SAD?

Just as a green plant requires sunlight to grow, your body requires sunlight for proper cellular functioning. 

When light enters your eye, it passes through the retina to your pineal gland. The pineal gland produces melatonin, an important neurotransmitter, which in turn influences the hypothalamus gland. The hypothalamus is responsible for controlling the body’s internal clock (sleep and wake cycles), appetite, metabolism, hormone production, reproductive function and mood.

In addition, the ultraviolet rays in sunlight are absorbed through your skin, triggering the production of vitamin D. Although it is possible to get vitamin D from fish or milk products, the form that you get from the sun is far more biologically active in your body. Vitamin D is crucial for the correct metabolism of calcium and phosphorus, which in turn keep the bones and teeth strong.

Those who spend too much time indoors, such as office workers, the homebound, and city dwellers, as well as those who live in the extreme North, frequently suffer from vitamin D deficiency. Among the elderly - especially those confined to hospitals or nursing homes - vitamin D deficiency is epidemic, contributing to the high incidence of breaks and fractures.

Reference: Health Sciences Institute, November, 1998 issue 

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What are the symptoms of SAD?

• decrease in energy levels 
• cravings for carbohydrates, sugar, and caffeine 
• insatiable appetite, leading to pronounced weight gain 
• sleep disturbances, including insomnia and/or difficulty in waking up 
• reduced sex drive 
• decreased cognitive abilities, such as attention and concentration 
• decreased immunity 
• mood disturbances, ranging from mild to severe

What are the problems with indoor lighting?

Sunlight, unlike any other light source on the planet, is composed of the entire spectrum of visible light frequencies - all the colors of the rainbow from red to violet - plus invisible ultraviolet waves. All of these components - including ultraviolet rays - are required for maximum health. 

Artificial indoor lighting is inferior to natural sunlight in two important ways. The brightest indoor lighting is equivalent to only 5 percent of the light you get outside on a sunny day, standing in the shade. In the course of an entire day indoors, you don’t get as much light as you get in a single hour outside.

The other problem with most indoor lighting is that it lacks a full range and even distribution of all of the colors in the visible light spectrum. While sunlight provides a more or less equal distribution of all the color frequencies from red to violet, indoor lighting provides an extremely uneven distribution, with an unnatural emphasis on the yellow and orange parts of the spectrum.

Partial-spectrum lighting makes it harder to make out words and colors on the page of a book or newspaper, causing headaches and eyestrain. But even more importantly, the lack of high-intensity full-spectrum light can quickly lead to symptoms of SAD or MIS, signals that your body is literally starving for light.

Reference: Health Sciences Institute, November, 1998 issue 

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How can full-spectrum lighting help me?

In the last 10 years, through the work of such pioneers as Dr. John Ott, Dr. Jacob Liberman, and Dr. Norman Rosenthal, light therapy - or phototherapy - has gained wider acceptance as a powerful, noninvasive healing method.

Mild cases of [SAD] can be alleviated simply by making an effort to spend at least one hour a day outside, without UV-blocking glasses or lenses.

If your symptoms are more severe, or if it is difficult for you to get outside because of work, disability, climate, or other reasons, you may want to consider phototherapy using a specially manufactured light box to provide high-intensity and/or full-spectrum light.

Light boxes are extremely effective in treating depression and other symptoms of malillumination. Most people feel a profound improvement in mood and energy in as little as two to three days. Even those without specific light-deficiency symptoms report waking earlier and easier and having better concentration and an increased sense of well-being when using light boxes.

Reference: Health Sciences Institute, November, 1998 issue 

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Aren’t UV rays unhealthy?

The matter of UV exposure is one of some controversy. Although many therapeutic benefits have been attributed to UV exposure - including decreased blood pressure, lower cholesterol, and improved thyroid function, UV light has taken a bad rap in recent years as the primary cause of wrinkles, skin cancer, and cataracts.

If you are going to be exposed to strong sunlight for long periods of time, you should use sunscreen to protect your skin from burning and UV-blocking sunglasses to protect your eyes. A small daily dose of sunlight on unprotected skin (and eyes) is a good idea, ensuring adequate vitamin D production and stimulating immunity. (Several studies have demonstrated that 10 minutes of unprotected exposure to natural sunlight three times a week results in fewer colds and respiratory infections.)

By getting your daily dose of sunlight in the morning or late-afternoon hours, avoiding unprotected midday exposure, you can enjoy the positive benefits of UV light while minimizing the potential risk to skin and eyes.

Reference: Health Sciences Institute, November, 1998 issue 

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What is this I've heard about light and PMS?

Several health practitioners have noted that many women with severe pre-menstrual syndrome (PMS) also suffer from SAD, and vice versa. Sunlight has a profound effect on the body’s hormonal production and regulation, which could explain why PMS or menopausal symptoms are often worse in the winter than in the longer days of spring and summer.

Many women have found that a daily session with a full-spectrum light box provides a quick, drug-free relief from menopausal hot flashes, as well as PMS symptoms like depression, irritability, and food cravings.

Reference: Health Sciences Institute, November, 1998 issue 

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Are the lights medically approved? Is a prescription needed?

In the sense that your doctor suggests and supervises the treatment, the method is approved. People don't need a prescription for light, but anyone suffering serious depression should certainly seek a doctor's recommendation before obtaining a unit, and use it under the doctor's supervision. Choose your doctor wisely, and question one who simply prescribes drugs such as melatonin or anti-depressants. Some doctors do not have knowledge of Full Spectrum nor Light Therapy.

Reference: SEASONAL AFFECTED DISORDER AND SYMPTOMS OF DEPRESSION: Light Boxes for the Winter Blues, "Why do I feel so down and depressed this time of the year?" by Tom MacKay

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Why does light therapy work?

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. 

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Will full-spectrum lighting cost me more or less in the long-run?

The Cost of Light is determined primarily by the cost of the electricity used to power the bulb. In fact, 80% to 88% of every dollar you spend on the cost of light is spent on electricity. Saving your family or organization money depends on investment in the most energy efficient lamps, since the purchase price of a bulb is only a small part of the total cost. For example, while the purchase price of a compact fluorescent may be higher than a standard incandescent, the payback in many applications can be three months or less. These spectrum bulbs can reduce your cost of light.

The chart below demonstrates the money-saving quality of full-spectrum fluorescents.