Dark Days, Darker Moods: Is It Seasonal Affective Disorder?
Sometimes the winter blues indicate something more serious.
by Kathleen Donnelly for MSN Health & Fitness
As the days darken during fall and winter, many people find their moods occasionally darkening too. But for an estimated 10 to 20 percent of Americans, the lowered light and colder temperatures prompt more than a temporary bout of the blues. They bring on a depression that is as predictable as the change of seasons: Seasonal Affective Disorder, or SAD.
"With the blues, you tend to have maybe one or two symptoms, and primarily they have to do with your mood," says Dr. Douglas Jacobs, associate clinical professor of psychiatry at Harvard Medical School and executive director of the nonprofit group Screening for Mental Health. "If you have Seasonal Affective Disorder, you'll have multiple symptoms. You not only feel down, you sleep too much, or lose interest in things, or overeat."
SAD is sometimes difficult to differentiate from other forms of major depression, Jacobs says, because some of the symptoms overlap: sadness, loss of interest in activities you once enjoyed and apathy, for example. But people who have SAD may also have extreme difficulty awakening in the morning and staying awake during the day. They may crave sweets and other carbohydrate-filled foods. They may overeat and gain significant amounts of weight. They may feel very tired and irritable, and find concentrating difficult.
"You may experience the blues for a couple of days, then you get some good news and you cheer up," Jacobs says. "With Seasonal Affective Disorder, you won't react so much to outside events."
And, most markedly, you may feel this way during the darkest months of the year –January and February are especially difficult for people with SAD – and not during the brighter days of spring and summer.
SAD was first identified only 20 years ago, and researchers still aren't sure what causes the problem. But from the start, scientists have suspected that the disorder is linked to light. After all, Jacobs points out, there is some evidence that the farther you live from the equator, the more likely you are to have SAD.
This may be because the low light of winter is linked to a biochemical imbalance in the brain. Because light suppresses the secretion of the hormone melatonin, the theory goes, people are exposed to more of the hormone during the short days of winter than they are during the long days of spring and summer. Researchers don't know exactly how increased melatonin affects people, but it may alter our cycles of sleeping and waking.
In addition, many studies have found that exposing people with SAD or more mild winter depression to bright light, both artificial and natural, can make them feel better, says Dr. David Avery, a professor of psychiatry and behavioral sciences at the University of Washington. Avery, whose research has centered on the timing of exposure to bright light, says that for most people morning exposure is most effective, whether the light comes from a specially designed fluorescent lamp, a dawn simulator that gradually becomes brighter, or the sun itself.
In most studies of light therapy, people have bathed in the bright light for a half-hour to two hours at a time, though Avery says exactly how much exposure a person needs tends to be individual and can decrease as therapy continues. What may be just as important, he says, is consistency.
"All of these light therapy studies have been done with instructions to the subjects to use the light at the same time every day, even on weekends," he says. "Many people in our culture sleep in on the weekends. In effect, when that happens, people are experiencing a kind of jet lag."
For people with more severe symptoms of SAD, getting help from your doctor is crucial. If your symptoms significantly affect your ability to function -- and especially if you have had thoughts of suicide -- get professional help quickly. Jacobs points out that in addition to light therapy, treatment with antidepressants and talk therapy can sometimes help. And although light therapy may seem like a simple idea, it's important to get direction on how and when to use it.
That's not to say people who have more mild winter depression can't help themselves, says Avery. For example, something as simple as putting a timer on a bedside lamp so that it lights 15 minutes before your alarm sounds may be enough to help some people who have trouble getting up on dark mornings.
Making a point to go outside even during the relatively weak light of winter is also a good idea. "One fact that many people are not aware of is that light outside, even on a cloudy day, is much brighter than most indoor light," says Avery. "People make the mistake of looking out the window, seeing it's cloudy, and thinking they aren't going to get much light if they go outside." If you can't get outside, he says, sitting next to a window during the day is "the next best thing."
Exercise may also help. While researchers have not studied its effectiveness with SAD specifically, Avery says exercise has been found to help with depression in general. Jacobs suggests getting at least a half-hour of exercise on three to four days a week – and exercising outdoors if possible.
"If you have mild symptoms, you can try some things and if they work, that's fine," Jacobs adds. "But if the symptoms really affect your daily life, get some professional help."