Psychotherapy Bests Light Therapy for SAD Sufferers

As winter approaches in the Northern Hemisphere and the days get shorter there, many people succumb to a disorder called seasonal affective disorder (SAD), a type of depression that is associated with shorter days.

SAD affects over 14 million Americans, according to researchers.

Writing in the American Journal of Psychiatry, researchers from the University of Vermont found that the traditional method of treating SAD, light therapy, does not work as well as cognitive behavioral therapy (CBT), a form of psychotherapy.

“Light therapy is a palliative treatment, like blood pressure medication, that requires you to keep using the treatment for it to be effective,” said University of Vermont psychology professor Kelly Rohan. “Adhering to the light therapy prescription upon waking for 30 minutes to an hour every day for up to five months in dark states can be burdensome.”

In the study, 177 subjects were given either six weeks of light therapy — “timed, daily exposure to bright artificial light of specific wavelengths using a light box” — or CBT to teach subjects how to challenge negative thoughts.

Their findings showed that two winters after the treatment, 46 percent of those who received light therapy reported that their depression had returned. Only 27 percent of the CBT recipients reported the same.

The depressive symptoms were more severe for those receiving light therapy, researchers said.

One reason could be that light therapy may be too burdensome, as the researchers report only 30 percent of the light therapy subjects were still treating themselves.

CBT, they said was more “preventative” in that it gave the subject tools to better deal with the symptoms of SAD.

In a companion study, the researchers found that over a shorter term, light therapy was as effective as CBT, but found that because of the number of people who stopped using light therapy, “CBT may be the better treatment option in the long term,” according to Rohan.