by Maria LaPiana
Dec 3, 2012
11:45 AMWell, Now
Caution: Dark Days Ahead
It casts a shadow in the lives of millions of Americans—many of them living in the colder, grayer regions of the Northeast. It creeps up slowly as the days grow shorter in fall and usually lasts well into spring. It manifests in a loss of energy, a sense of hopelessness, a penchant for sleep and, often, an intense craving for cookies.
It hits Frances B. of Danbury like clockwork every September and worsens as the days shorten. “I start to feel blue when my kids go back to school. I get up early to make breakfast and pack lunches and I really notice my mood changing when I let the dog out and it’s still dark,” she says. “I spiral downward from there.”
What clouds Frances’ days is seasonal affective disorder, or SAD (an appropriate acronym if ever there was one). Also called the “winter blues,” the syndrome—which mimics clinical depression in many ways—is caused primarily by a scarcity of sunlight. Consistently overcast skies are believed to disrupt the body’s circadian rhythm, or the internal clock that lets us know when to sleep and wake up.
It can be debilitating. “Some patients say they lose half their life,” says Dr. Paul Desan, director of the Winter Depression Research Clinic at the Yale School of Medicine. “They shut down every fall and come alive again in the spring.”
Estimates put the number of Americans afflicted with SAD at 10 million or more.
Says Desan, who has been conducting clinical studies of patients with SAD since 2002: “Winter depression is an important public health problem at [Connecticut’s] latitude. With incidence rates rising the farther away you get from the equator, the disorder is far more common in Canada, but they have much more public knowledge of the condition and how to treat it.”
That’s cause for concern, according to Seth D. Ginsberg of the New York-based Global Healthy Living Foundation. “SAD is a chronic illness that has only recently been documented, and studies that demonstrate what contributes to it, how to treat it, and its impact on the patient, are still in the early stages. But despite an absence of data, it is still a serious problem,” says Ginsberg. “Understanding the effects of seasonal changes can help improve a person’s quality of life.”
Okay, so many of us would agree that winter in general isn’t so cheery; we move less, eat more, feel tired and long for warmth—that’s depressing. What of patients who are prone to depression anyway? How do they know if they have SAD?
Symptoms may include fatigue, loss of interest in enjoyable activities, poor concentration, indecisiveness, heaviness of arms and legs, irritability, cravings for starch, carbohydrates and alcohol—but seasonality is key. Unexplained anxiety in late summer will often precede the onset of SAD symptoms, which tend to abate whenever we’re exposed to the sun (when we go on vacation, for example). And it’s SAD only if you suddenly feel focused and your mood lifts every spring.
In Desan’s experience, nine out of 10 people who volunteer to participate in his research say that they generally feel worse in winter, but only two or three percent experience “very significant changes in season that meet the definition” for the disorder.
Women with SAD outnumber men by three to one, he says. “Vulnerability to depression does depend on estrogen and progesterone levels,” he says, “and there’s quite a correlation between premenstrual syndrome and seasonal affective disorder, so hormones definitely come into play.”
The best medicine for SAD is, not surprisingly, light—and lots of it.
“It’s been established that treatment with bright light in the morning is unquestionably the most effective treatment for the condition,” according to Desan. It isn’t enough to turn on all the lights in the house, though; studies have shown exposure needs to be intense and focused. To provide that, there are a host of light-therapy boxes on the market now. When used for 45 minutes to one hour every day, the devices have provided relief for patients for years. The boxes, which cost anywhere from $100 to $500, should provide 10,000 LUX of illumination at a comfortable sitting distance. Some simulate sunrise by brightening gradually at preset times, while others emit a steady glow. “It’s not that it makes you feel better immediately, that day or even the next,” says Desan. The treatment is cumulative and may take several weeks to achieve the full effect.
There are problems with light therapy, however. Medical-grade light boxes are bulky, for one; most measure 24 inches across and 18 inches high. In recent years, Desan and his colleagues have been experimenting with smaller devices that operate with the use of light-emitting diodes. “We’ve learned that the body’s clock responds to shorter waves of light, that it doesn’t need broad spectrum light, so we’re working on several different devices, smaller ones that are battery-powered and operate with small diodes,” he says. And light-therapy sessions take time. “We’ve found that the smaller boxes work at least as well as—and are faster than—large light boxes,” says Desan. “We’ve seen that 30 minutes with the new device is as good as 60 minutes with the old.
“I’m a scientist and am not affiliated with any manufacturer; I only recommend things that are documented,” he says. “The overwhelming clinical consensus is that a large box isn’t necessary. Our goal is to have a smaller, better light box approved by the FDA within the year.”
Another concern is that most consumers simply don’t know what to look for in a light box. “Some are very appropriate, while others are not likely to work at all,” according to Desan.
There are also dangers. Stay away from anything that doesn’t thoroughly filter UV light, he says, and always consult your physician if you have diabetes or any kind of retinal disease, as light therapy would most likely not be recommended in these cases.
For more information on SAD research and treatments, contact the Society for Light Treatment and Biological Rhythms (sltbr.org).