Seasonal affective disorder (SAD) goes beyond the winter blues. It goes beyond feeling tired or sad or disliking winter. SAD is a form of clinical depression that occurs in the winter, according to Kelly Rohan, Ph.D, associate professor of psychology at the University of Vermont, whose research focuses on SAD. It starts around fall or winter, as the days get shorter and darker, and typically remits in the spring or summer.
SAD affects around 14 million Americans, according to author and SAD specialist Norman E. Rosenthal, M.D., in his book Winter Blues: Everything You Need to Know to Beat Seasonal Affective Disorder. (About 14 percent of American adults struggle with the winter blues.)
People with SAD experience a variety of physical, emotional and cognitive symptoms that impairs their daily functioning. They’re usually unable to perform at school or work and have difficulty interacting with others. Tasks that once seemed simple, such as household chores or paying the bills, suddenly become overwhelming.
The ability to think clearly also becomes impaired. In fact, according to SAD expert Dr. John Docherty, the disorder causes many problems for people at work. Dr. Rosenthal cites Docherty in his book. He lists these at-work problems by how often they occur: “decreased concentration, productivity, interest, and creativity; inability to complete tasks; increased interpersonal difficulties in the workplace; increased absences from work; and simply stopping work.”
According to Rosenthal, the physical symptoms can be especially prominent and debilitating. They include sleeping problems, fatigue, a revved-up appetite, loss of interest in enjoyable activities and diminished sex drive. And while mood changes are salient, individuals may feel the physical signs first. In the book, a middle-aged woman describes her physical symptoms:
I don’t really feel depressed. I just feel like all my systems have been turned off for the winter. I feel leaden and heavy and just want to lie about all the time. It’s only when I am expected to do something out of the ordinary, and I realize that I cannot do it, that I feel my mood being pulled down.
Light therapy, cognitive-behavioral therapy and antidepressants are effective in treating SAD. In 2006 the Food and Drug Administration approved the antidepressant Wellbutrin XL for preventing episodes of SAD.
Extensive research has shown that light boxes work well in boosting mood and energy. Light boxes emit artificial light that mimics the sun’s rays. They emit anywhere from 2,500 lux to 10,000 lux. (Lux is a measure of intensity.) Light therapy requires a daily commitment. It’s best to use light boxes in the early morning for 30 minutes or more during the winter months. (The 2,500-lux light boxes might even require two hours.) However, you can read or talk on the phone as you’re receiving light therapy. According to Rosenthal, you can do anything during your sessions, as long as your eyes are open, you’re facing the light box and there’s a proper distance between you and the box.
Early research has shown that CBT for seasonal affective disorder may be even more effective than light therapy (and doesn’t require the extensive time commitment as light boxes do). In this 2009 study, Rohan and colleagues compared SAD-tailored CBT to light therapy (along with a combination of both treatments and a wait-list condition). They found that CBT, light therapy and both CBT and light therapy were all effective in treating SAD.