January 10, 2005
Light Boxes Help Lift the Winter Blues
They ease depressive symptoms caused by seasonal affective disorder, research finds
HealthDayNews -- Few people relish the cold, short days of winter.
For many, there's good reason: Experts believe that about one in five Americans suffers from either mild or severe forms of seasonal affective disorder (SAD), which can lead to depression, overeating, weight gain and fatigue.
Fortunately, this is one condition where drugs aren't the best answer. A new study confirms that simply sitting next to a light-emitting box for a half-hour a day greatly reduces SAD symptoms.
"Bright light treatment is definitely the treatment of choice for SAD," said lead researcher Randall Flory, a professor of psychology at Hollins University, in Roanoke, Va.
Flory's study, presented at a recent meeting of the American Psychological Society, also found that room air ionizers -- which increase levels of negatively charged particles circulating in air -- can help ease the symptoms of SAD.
According to Flory, about 14 percent of Americans admit to feeling "blah" during the winter months. "They have the lesser form of SAD, which we just call the 'winter blues,'" he said. "It's not as debilitating as full-blown SAD."
Another 6 percent to 7 percent of people may experience full-blown SAD, which can include clinical depression, overeating and related weight gain (up to 40 pounds per season), excess sleep followed by daytime fatigue, a heightened sensitivity to pain, and social withdrawal.
Premenopausal women are four times more likely to be affected by SAD than men, Flory said, suggesting links between SAD and the female hormones estrogen and progesterone.
While popular antidepressants such as Prozac, Zoloft and other selective serotonin reuptake inhibitors (SSRIs) have shown some effectiveness in treating SAD, non-medicinal methods are proving even more powerful, he said.
In their study involving 140 women observed over five successive winters, the Roanoke researchers compared the effectiveness of two non-pharmaceutical treatments: 30 minutes per day of home exposure to light-emitting boxes, and air-cleaning devices that also produce negative ionization of airborne particles.
Light boxes were the clear winner, Flory said, although the air ionizers were also somewhat effective. The results suggest that a combination of winter conditions -- fewer hours of strong sunlight, as well as weaker negative ionization of air -- work together to affect humans in a physiological way.
"From previous studies, we know that just about everybody, whether they have SAD or not, shows lowered levels of serotonin in the brain in winter compared with summer," Flory said.
SSRIs work by adjusting brain serotonin levels, so it makes sense that they fight SAD. But Flory believes most patients are better off using light boxes, since they have virtually no side effects and are much cheaper than prescription drugs over the long term.
Use of a standard light box for five years works out to "about $60 per year," Flory noted, "compared to about $300 to $500 per year for Prozac or another of the SSRIs."
Michael Young, a SAD expert and director of clinical training at the Illinois Institute of Technology in Chicago, agreed that "light boxes are certainly the most effective treatment" for seasonal depression.
New variations on light boxes are giving patients more choices, he said, including devices called "dawn simulators." These devices -- hooked up to a bright light in the bedroom -- cause light to slowly grow in intensity during the early morning hours, much as it would on a spring day.
"There's been less research done on dawn simulators compared to light boxes, but the research that is out there seems to have gotten positive results," said Young, who is also president of the non-profit Society for Light Treatment and Biological Rhythms.
He stressed that scientists still aren't sure why some individuals are more deeply affected by winter than others.
"For example, there are many of us that have the physiological changes but not the psychological ones -- they'll say 'Yeah, winter is crummy, I sleep more, I want to eat sweets all the time, but, hey, that's the way it goes.' They aren't depressed."
Others experience those physical signs, plus the debilitating depression that marks severe SAD. Young believes some people may simply be more neurologically vulnerable to season-to-season changes than others.
For most, light boxes provide an easy, harmless solution, the experts agree.
"You just sit three for a half hour a day, that's all it takes," Flory said. "It's not even necessary that it's there in front of you --- only that the light somehow enters your eye. In fact, when we do studies, the light box is over to the side while people watch a movie on television."
To learn more about SAD, visit the National Mental Health Association.