1. What is light therapy?
Bright light therapy involves daily, scheduled exposure to intense doses of white light in order to regulate seasonal mood swings, improve sleeping patterns, and produce a general sense of well-being. According to medical researchers, bright light therapy systems with fluorescent light tubes is the preferred device for bright light therapy, with a recommended starting dose of 10,000 LUX for 30 minutes per day. (LUX is the unit of measuring the illumination intensity of light.)
2. What is light therapy used for?
Bright light therapy was originally tested and developed by medical experts in the early 1980's for treating Seasonal Affective Disorder (SAD) - a type of recurrent, major mood disorder regularly experienced by some people during the fall and winter months. Those with SAD are often quite incapacitated by depressive episodes and require medical treatment. During the spring and summer, however, their symptoms usually disappear.
More recently, researchers have explored the benefits of using bright light therapy on people with "subsyndromal" SAD - commonly known as the "Winter Blues," and studies indicate a good response rate. Other conditions for which bright light therapy looks promising include non-seasonal mood disorders, bulimia nervosa, panic disorder and premenstrual syndrome (PMS). Doctors who use lights with pregnant women to avoid pre- and post-natal blues have reported encouraging results. Other studies show bright light therapy useful in certain disorders of the circadian system (i.e., the internal biological clock) including circadian sleep phase disorders, shift work, and jet lag .
3. What is the difference between Seasonal Affective Disorder (SAD) and the Winter Blues?
Many people, especially in northern latitudes where winter hours of daylight are fewer, complain of feeling down, having less energy, putting on weight and having a hard time getting up in the morning. This is what we refer to as "having the Winter Blues."
Although there are variances among individuals, most people with SAD experience all of these symptoms, but to a much greater degree. They are often despondent and fatigued, and want to withdraw from the world. They may increase their sleep by as much as four or more hours per day, or have greatly increased appetites - sometimes accompanied by extreme cravings for sweet and starchy foods. Women frequently report worsening of premenstrual symptoms. In short, people with SAD suffer in the extreme the kinds of changes most of us experience in wintertime, and require medical treatment - either light therapy or antidepressants .
4. How prevalent is SAD?
According to a recent report published by the Canadian Consensus Group for the Treatment of Seasonal Affective Disorder (please see reference section), SAD is conservatively estimated to occur in up to 3% of the Canadian population, and 1% of the US. For recent population figures, that means as many as 3 million Americans and 900,000 Canadians suffer from SAD.
The number of people, however, who experience the Winter Blues is much greater. A recent estimate suggests eleven times as many people suffer from the Winter Blues as are diagnosed with SAD, and some studies indicate as much as 25% of the Canadian population experience some degree of winter doldrums. Women are at least twice as likely to have SAD as men .
5. How do I know if I could benefit from using a bright light system?
You could benefit from using a bright light system if you experience any combination of the following symptoms during the winter months:
6. Have bright light systems been proven to work?
Yes. Since the first controlled light therapy study in 1984, there have been more than 60 controlled studies published by researchers around the world. Experts are now confident that bright lights work for the majority of people with SAD. (Response rates of 60% to 90% have been shown). Accordingly, a report called the Canadian Consensus Guidelines for the Treatment of Seasonal Affective Disorder (published in 1999 and partially funded by Pfizer) recommends bright light therapy as an effective first-line treatment for SAD.
Several controlled studies have also found bright light therapy beneficial for those with subsyndromal SAD (Winter Blues), and its effects on human body rhythms, independent of any effects on mood, are recognized (e.g., for shift work or jet lag). Although medical researchers are hesitant to make treatment recommendations without further research in these areas, the Canadian Consensus Group considers existing studies "encouraging".
7. How do bright lights work?
The exact cause of Seasonal Affective Disorder has yet to be scientifically proven, and so the mechanism by which bright light therapy work remains hypothetical. However, bright light therapy has been statistically proven effective in the treatment of SAD, which puts the role that daylight plays in regulating our daily body rhythms in the forefront of research.
8. How long does it take to experience the benefits of using bright light therapy?
Response to bright light therapy is usually very quick, and most people will notice a marked improvement within one week. Most people similarly experience a rapid recurrence of symptoms if they stop using their bright light therapy system.
Longer trials have also shown increasing response to bright light therapy after two weeks, with still more incremental improvements after three or four weeks. Therefore, it is recommended that you continue to use a bright light therapy system for at least a month before concluding it will not help you.
9. Could I get the same benefits by increasing the lighting in my home and office?
If you are particularly light-sensitive, you may feel more uplifted with increased exposure to increased room lighting. However, research studies show that much higher light intensities (at least 2,000 LUX) are required in order to produce the desired therapeutic effects, and it is just not possible using regular fixtures to get ambient lighting above 600 LUX.
Note also that medical experts caution against constructing your own bright light apparatus because of possible electrical hazards, as well as the difficulty in determining adequate light intensity and ensuring ultraviolet (UV) light rays are properly filtered .
10. What about spending more time outdoors -- would that work?
You should be able to satisfy your need for light by spending more time outdoors during the fall and winter days, as long as you can be outdoors regularly and for extended periods of time if conditions are cloudy. Most people find that difficult to do if they work indoors and have to keep an office schedule. The use of a 10,000 LUX bright light therapy system is therefore the most convenient way to get the light you need.
11. Are there any side-effects from using bright light systems?
Using a properly constructed bright light therapy system as recommended is considered very safe, and few people have to desist use because of side effects. A few temporary side effects, such as slight nausea, tend to pass quickly as you get used to the high intensity of light.
The majority of side effects, such as headache, eye strain, agitation, insomnia or difficulty getting to sleep, are caused by overdoing light therapy sessions. (In this case, it is possible to get "too much of a good thing.") Such symptoms usually disappear when you decrease the "dosage" of light to your optimal level (usually in the 20 to 30 minute range).
If you have clinically diagnosed SAD, you may experience other personal variances which should be assessed and monitored by your doctor.
12. What if I'm on antidepressants, can I use lights?
That depends. If your episodes are not seasonally triggered, it is unlikely that a bright light therapy system alone will alleviate your symptoms. However, a bright light therapy system may help uplift your mood, and, if your doctor recommends it, can be used in conjunction with your medication.
For treating SAD, bright light therapy systems are recommended as the first-line, "gold standard" treatment. Many people enjoy remission of symptoms simply by using bright light therapy. Others may not respond at all, though they are in the minority. Still others may use medication in conjunction with bright light treatment. Since individual requirements can vary widely, your treatment regime should be supervised by your doctor .
13. When is the use of a bright light system not recommended?
There are no absolute contraindications to bright light therapy. However, if you have any eye problems (e.g., glaucoma, cataracts, retinal detachment, retinopathy) or have predisposing factors for eye complications (e.g., diabetes, lupus), or if you are using medicated externally applied creams or lotions (e.g. Retin-A) or if you are taking medications that have photosensitizing effects in humans (e.g., lithium, melatonin), you should not use a bright light therapy system without first consulting your physician. Your doctor will need to assess your individual risk-benefit ratio of using bright light therapy
CAUTIONS Light energy can interact with and damage skin and eye tissues, especially when a photosensitizing molecule - whether from a drug or produced by the body - is bound within those tissues. The highest risk is with invisible ultraviolet (UV) light, which has been filtered out of the Day-Light system. In addition, there are certain pre-existing medical conditions of eyes and skin (e.g., retinal dystrophies, age-related macular degeneration, porphyria, lupus erythematodes, chronic actinic dermatitis and solar urticaria) that can show photosensitized reactions to intense visible light. In such cases, bright light therapy should be administered only under guidance of an ophthalmologist or dermatologist, as indicated. Ophthalmologists should keep in mind that in some genetic retinal diseases the eyes are especially light-sensitive. Certain medications also are known to photosensitize skin and/or retinal tissues. Examples in the visible range of light include neuroleptic drugs (e.g., phenothiazine), psoralen drugs, antiarrhythmic drugs (e.g., amiodarone), antimalarial and antirheumatic drugs, porphyrin drugs used in photodynamic treatment of skin diseases, and St. John's Wort (hypericum). Bright light therapy should not be used concurrently with these drugs. Melatonin can be used in conjunction with light therapy at opposite times of day (e.g., evening and morning), but if used concurrently, it can cause photosensitization. Drugs that photosensitize primarily in the UVA range (just below 400 nm) may also have a "tail" of light absorption that extends into the lower visible range (just above 400 nm), which could cause photosensitization. Examples are tetracycline, diuretic drugs (e.g., hydrochlorothiazide), sulfonamide drugs and tricyclic antidepressants (e.g., imipramine, nortriptyline, desipramine, amitriptyline). If such a reaction is experienced or suspected, bright light therapy should be discontinued unless substitute medication is available, or administered with protective measures under medical supervision. [Sources: Vincent DeLeo, M.D., St. Luke's-Roosevelt Medical Center, New York; Charlotte Remé, M.D., University of Zurich, Switzerland.]
14. Are bright lights medically approved?
At this point in time, no bright light therapy systems are approved as "medical devices" by government regulatory agencies in either the US or Canada. However, in so far as researchers have proven the effectiveness of bright light therapy and recommend it as a first-line treatment for SAD, bright light therapy systems have gained recognition of the medical community. To ensure that you choose an effective product, it is important to follow the guidelines of recognized experts and professional bodies to ensure that you select products that meet these strict, third-party guidelines. The Center for Environmental Therapeutics is one of these organizations (www.cet.org).
15. Are lights covered under my medical insurance, and do I require a prescription?
Many private insurance companies recognize the benefits of bright light therapy, its cost advantages over medication and will cover the purchase of a bright light therapy system with a prescription from your doctor. You should contact your insurance company before making the purchase to discuss coverage and determine their specific documentation requirements.
In North America, bright light therapy systems are not approved for reimbursement under government health insurance, but are widely available for purchase without a prescription. For more information, click here.
16. Why do research experts and medical doctors recommend the Day-Light system for light therapy?
Day-Light Bright Light Therapy Systems, manufactured by Uplift Technologies Inc., are recommended by doctors because they have been used in, or been designed to meet the standards for, clinical studies. Day-Lights have been the choice of leading researchers around the world since 1989 and been shown to be safe and effective.
Day-Light Bright Light Therapy Systems were selected by Dr. Raymond Lam, Medical Director for the Mood Disorders Program at the University of British Columbia Hospital, for use in a three-year, 200-person controlled study of bright light therapy for treating SAD. Dr. Lam says he selected Day-Lights because "they use the latest technology, are of excellent quality, durability and aesthetics, and meet all recommended safety standards. The company also has a track record of dependability."
17. What is the correct way to use Day-Lights for therapy sessions?
For bright light therapy sessions, you would use your Day-Light each morning for 20-30 minutes during the fall and winter months. To receive 10,000 LUX, you need to sit approximately 11 to 15 inches from the light. During the session, you should NOT look directly into the light, but read, eat breakfast or check your e-mail.
18. Why do I need 10,000 lux?
10,000 LUX for 30 minutes in the morning is what the experts recommend as a starting dosage for bright light therapy. Individuals may need to adjust the duration up or down from the 30 minute dose, or use the light at a different time of day, depending on their individual response to treatment. While you can get the appropriate dosage of light using a 2,500 LUX system for two hours per day, this is far less convenient for most people. Our Day-Light Bright Light Therapy Systems provide 10,000 LUX at 11 - 15 inches.
19. Can Day-Lights be used in other ways?
The quality of the light emitted by Day-Lights is very pleasant, and may be enjoyed outside the context of bright light therapy. Positioned at arms length (i.e., farther than the 11-15" distance for light therapy), or directed away from the face, they make excellent ambient, reading and task lights. Lightweight and portable, Day-Lights can be used for a variety of purposes.
20. Do Day-Lights cause tanning?
Day-Lights do not cause tanning because the ultraviolet (UV) rays that cause tanning are filtered out (99.3%). Medical experts caution that exposure to unfiltered bright lights for extended periods of time may eventually cause ocular damage. Be wary of "full spectrum" lights unless they are UV filtered.
Please click this LINK to see the spectral distribution graph for Day-Lights.
21. Are Day-Lights expensive to buy and maintain?
The retail price for quality-made, name-brand bright light systems is between $300 and $500. The suggested retail price for Day-Light models ranges from $189 - $229, but actual prices may vary. Day-Lights conform to all technical design guidelines recommended by medical experts for bright light therapy systems:
22. What if the Day-Light doesn't work for me?
Often a 1 - 4 week trial period is enough to determine if the Day-Light Bright Light Therapy System will be effective for you. Many vendors offer return options or may have rental programs where your "rent" is applied to the purchase price. Ask your vendor for details before purchasing.
23. How do I dispose or handle old fluorescent light tubes?
To ensure safe handling of old light tubes, always dispose of light tubes in accordance with local disposal regulations. For current information on fluorescent light tubes, please visit: www.lamprecycle.org, www.epa.gov in the US or www.hc-sc.gc.ca in Canada
References & Further Reading