It goes by many names. Seasonal Adjustment Disorder, Seasonal Affective Disorder and SAD syndrome. But you probably know it by just one: the winter blues.
No matter how cheerful and even-keeled we may be throughout the year, studies show that all animals — human and otherwise — react to the onset of winter and loss of light both physiologically and psychologically. While some of us may simply sleep more or suddenly develop an uncontrollable craving for chocolate, up to 20 percent of Americans suffer greatly from a serious form of depression doctors call "SAD."
Typical symptoms of SAD include oversleeping, overeating (especially sweets), depression, lethargy, stomach and joint pain, and lowered immune system function. Women are particularly susceptible to SAD, comprising 70-80 percent of those affected, and not surprisingly, the incidence rate of severe cases rises dramatically the further one is from the equator.
Natural Light and SAD
Though the causes of SAD are not completely understood, researchers agree that light plays a vital role. Just as with plants, human beings wither without it. Studies show that light deprivation alters brain chemistry, triggering over-production of melatonin, which causes fatigue (in fact, many people use melatonin as a sleep aid).
Because 70 percent of our sensory receptors are in our eyes, visual stimulation and exposure to light are critical to well-being. Based on that fact, researchers hypothesized that by increasing the amount of natural light SAD patients are exposed to daily, — a process called photo- or bright light therapy — symptoms would decrease. And they were right.
In 1984 a breakthrough study conducted by Dr. Norman Rosenthal concluded that bright light therapy minimized the effects of SAD. Though other treatments have proven useful in combating the illness, including daily outdoor exercise and prescription mood enhancers such as Paxil® and Zoloft®, photo therapy has become the preferred treatment method because it can be administered in any weather conditions, it is relatively inexpensive, and it is non-addictive.
Natural Lighting's Broad Benefits
Some in the lighting industry were well ahead of the curve in understanding the health benefits of natural light. In 1956, Howard Scott founded Verilux® and invented a line of lighting products "refined to include the best of natural daylight without the unnecessary wavelengths." In 1989, after 40 years of research on "the remarkable effects natural light had on plants, animals and humans," Dr. John Ott and Fred Mendelsohn founded Environmental Lighting Concepts (parent of OTT-LITE), based on the idea of simulating natural light indoors. These developments revolutionized the lighting industry, enabling customers to enjoy the therapeutic benefits of sunlight when it is difficult or impossible to find it outdoors.
Natural light simulating products are commonly referred to as “full spectrum” lights, which have a color temperature of between 5,000-6,500° Kelvin and a Lux output of 10,000 (Kelvin is a measurement of heat, based on absolute zero; Lux is a measurement of the intensity of light as it is spread across a room). Studies show that optimal therapeutic benefits of SAD lamps are derived at 10,000 Lux because the quantity of light reaching the eye determines the light’s effectiveness. That is why most (if not all) full spectrum lamps have a 10,000 Lux rating.
Research indicates that using these lights not only elevates mood and produces a healthier living and working environment, but it may even alleviate some of the suffering attributed to Alzheimer’s Disease and help create a positive learning environment in school classrooms. In a study conducted by the Netherlands Institute for Brain Research, researchers concluded that simulated sunlight diminished some of the symptoms of Alzheimer’s Disease by creating a more calming indoor atmosphere. Similarly, Alberta Education’s Policy and Planning Division found that natural lighting has a positive impact on the productivity and physical development of students. According to a study published in 1992, students who worked in classrooms illuminated with full spectrum light grew taller, attended class more regularly and achieved higher scores on the Canadian Test of Basic Skills.
Find Your Smile, Save Your Eyes
Today, OTT-LITE, Verilux® and Design Classics® offer natural light-mimicking product lines that produce broad benefits beyond combating SAD. Eyestrain reduction and true color rendering—revealing colors as they are seen in broad daylight, not tinged yellow or blue as they appear under most traditional white light bulbs—are two of the main advantages of natural lighting. A third is the prevention of blurry vision and headaches often attributed to the “stroboscopic effect” that conventional fluorescent tubes emit.
Used by jewelers, artists, the elderly and anyone who wants clear and soothing illumination, sunlight simulating products generate an abundance of positive results. “While there is no amount of ordinary light that can replace the clarity or benefits you can get from natural light, the next best thing is simulated light,” says Dr. Ott. Dr. Ott's research indicates that even animals gain significantly from full spectrum light—especially caged birds, which exhibit fewer behavior problems and experience less feather loss.
While most of us don’t experience the extreme depression of SAD, we can all profit from exposure to full spectrum light. Whether it’s reading for long periods of time, working on a computer, doing needlework or simply resting after a long day, SAD lights improve the quality of everyday activities by increasing clarity and providing the health benefits of daylight indoors, in any setting. So, heed the experts’ advice and experience natural indoor lighting today—raise your spirits, save your eyes and see what you’ve been missing.
Sources
- American Psychiatric Association, healthyminds.org
- Family Doctor, www.familydoctor.org
- Nature magazine, "Malatonin Sensitivity to Dim White Light in Affective Disorders." www.nature.com/npp/journal/v21/n3/full/1395342a.html
- "Winter Blues." Norman Rosenthal, Guilford Press, 1993; "Seasonal Affective Disorder and Phototherapy." Norman Rosenthal, Ed., Guilford Press, 1989.
- "Bright Idea for Alzheimer's." BBC News, 7.24.98. www.news.bbc.co.uk/1/hi/health/138879.stm
- "The Advantages of Full Specturm Lighting." Ambrose Paul Wasdyke, Jr.CEE News, 1.90.
- Verilux, Inc.
- OTT-LITE Technology
