The benefits of cognitive behavioral therapy — a form of talk therapy — outlasted light therapy sessions for people suffering from SAD, according to a study published Thursday in the American Journal of Psychiatry.
"Light therapy is a treatment that suppresses symptoms as long as you're using it," said lead author Kelly Rohan, a psychology professor at the University of Vermont. "So if you're not using it, there's no reason to expect the continued benefit for a treatment that works that way, whereas cognitive behavioral therapy teaches skills."
And the people who learn those skills can use them long after their therapy sessions.
For the study, researchers tracked 177 people who suffer from major depression that follows a recurring seasonal pattern. About half of the subjects received six weeks of daily light therapy; the others received 12 sessions of cognitive behavioral therapy over the same period of time.
In the subsequent year, subjects were encouraged to apply the skills they learned in therapy or to seek out light therapy again. While both treatments initially "produced large improvements," those improvements dwindled after awhile, Rohan said. Two winters after the treatments, 46 percent of those who had received light therapy had a recurrence of depression, compared to just 27 percent of the cognitive-therapy subjects.
"I take this, to me, evidence of the durability of cognitive behavioral therapy treatment," Rohan said.
Cognitive behavioral therapy’s aim is to change the negative thinking patterns and behaviors associated with depression. The theory behind light therapy is that it simulates an early dawn and "can jump start circadian rhythms" that become sluggish during dark, cold months, Rohan said.
"A small body of research" shows thoughts and behaviors play a role in SAD, Rohan said, and cognitive behavioral therapy puts "the person in the driver's seat" in facing depression and gives patients a sense of agency and control. That's opposed to medication and light box therapy, things that are administered, she said.
"For patients with SAD and providers who treat SAD, there's another way," Rohan said. "We can think outside of the light box. The good news is we can change our thoughts and behaviors. We can't change what time the sun rises and sets."
For more health news, you can sign up for our weekly newsletter here.