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One Psychologist On What Causes Seasonal Affective Disorder, And How To Treat It

A man makes his way home from work on a bus as darkness falls in Glasgow, Scotland. (Christopher Furlong/Getty Images)
A man makes his way home from work on a bus as darkness falls in Glasgow, Scotland. (Christopher Furlong/Getty Images)

About 5 percent of people in the U.S. suffer from seasonal affective disorder, a form of depression brought on by the dark days of winter. Many more may experience a mild form of the disorder.

Kelly Rohan, a professor of psychology at the University of Vermont who researches seasonal affective disorder, says the term wasn’t coined until 1984 by a psychiatrist named Norman Rosenthal, who had moved to Bethesda, Maryland, from South Africa.

“He felt that he experienced these symptoms of depression when he made this move, and put out an ad in The Washington Post: ‘Does anyone feel depressed in the wintertime?’ ” Rohan tells Here & Now‘s Jeremy Hobson. “And apparently the phone rang off the wall for several days.”

Interview Highlights

On what seasonal affective disorder is

“Seasonal affective disorder, or SAD, is actually a type of depression. The only thing that makes it different is the seasonal pattern that it follows, where the symptoms are in effect during the fall and the winter months, and they fully resolve or go away during the spring or the summer months. So when we’re diagnosing SAD, we are in fact diagnosing depression, and we’re looking for exactly the same symptoms that we see in depression, like feeling fatigued, sleep changes, appetite and weight changes, loss of interest in activities, difficulty concentrating, sometimes thoughts of death or suicide.”

On whether SAD has to do with light, cold or a combination

“It’s about the light. The research is pretty clear that it’s about day length, or photoperiod — simply the number of hours from dawn to dusk is the strongest predictor of when the symptoms begin in any given year, and how bad they are on any particular day in someone that suffers from seasonal affective disorder.”

On groups of people that are especially susceptible

“Women are particularly susceptible, much more so than men. At least two times the number of women as men suffer from seasonal affective disorder. It also looks like younger adults are more susceptible, people in their 20s or their 30s. People who live at a high latitude are particularly susceptible, although it does exist in Florida — it’s relatively rare compared to, for example, where I am, Burlington, Vermont.”

On treatment options

“There’s at least three treatments with a strong research base. There’s light therapy — use of a device that projects bright light to the retina first thing in the morning to sort of jumpstart sluggish circadian rhythms and reset the biological clock. There’s a lot of research to show that light therapy is a highly effective treatment for winter depression. Antidepressant medications, the same ones that are used to treat non-seasonal depression, the SSRIs in particular, such as Prozac. There’s a drug called Wellbutrin XR, which is FDA approved for the prevention of winter depression specifically. And then third, other than light therapy and medications, there’s a form of talk therapy or psychotherapy called cognitive behavioral therapy that’s effective in treating SAD, but also seems to be effective in preventing the return of symptoms after the treatment has ended.”

On whether it helps to take a trip somewhere warm and sunny

“It most definitely does. My word of caution about doing that has to do with re-entry. So, people with seasonal affective disorder uniformly say that they feel so much better when they travel to a warm, sunny location, and it’s almost immediate within a few days of getting there. They feel great, they feel like they do in the summer. However, we have to then go back to wherever you’re coming from, farther north, and that re-entry can be pretty jarring for the biological clock.”

On if the condition has been around for a long time, or is new

“This condition has been around for a very long time. We can see it in the writings of ancient philosophers and physicians, writing about the effects of light on mood, and even precursor to modern-day light therapy, talking about ‘laying lethargic in the light, so that we can cure their disease, which is gloom.’ “

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