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Light therapy, cognitive-behavioral therapy have comparable efficacy for seasonal affective disorder

Results from a randomized trial indicate light therapy and cognitive behavioral therapy had similar efficacy in treating acute episodes of seasonal affective disorder.

“We previously developed and tested a group of cognitive-behavioral therapy adapted for [seasonal affective disorder] in an initial feasibility test and a controlled randomized trial. These preliminary studies, included 84 adults with [seasonal affective disorder], found comparable and large symptom improvements in patients receiving cognitive-behavioral therapy for seasonal affective disorder and those receiving light therapy,” Kelly J. Rohan, PhD, of department of psychological science at the University of Vermont, and colleagues wrote.

Kelly J. Rohan

To further assess efficacy of cognitive behavioral therapy for seasonal affective disorder (CBT-SAD), researchers randomized 177 adults with a current episode of major depression that recurred seasonally to light therapy or CBT-SAD. Light therapy was 30 minutes of 10,000 lux cool-white florescent light initiated each morning and then adjusted according to a treatment algorithm for response and side effects.  CBT-SAD was 12 group sessions that were 90 minutes long and occurred twice weekly. They assessed seasonal affective disorder and depression outcomes before treatment, at week 3 and after treatment.

Both therapy groups experienced significant and comparable improvements in depression severity. Study participants who had a comorbid diagnosis at baseline were more likely to have higher depression scores at all times during the study period, regardless of treatment type.

Remission rates did not differ among treatment groups for CBT-SAD vs. light therapy for the Structured Interview Guide for the Hamilton Rating Scale for Depression SAD Version (47.6% vs. 47.2%) or the Beck Depression Inventory Second Edition (56% vs. 63.6%).

“These findings suggest that CBT-SAD and light therapy are comparably effective treatment modalities for targeting acute seasonal affective disorder. Accordingly, CBT-SAD should be disseminated into practice and considered as a viable alternative to light therapy in treatment decision making,” Rohan and colleagues concluded. – by Amanda Oldt

Disclosure: Rohan reports financial ties with Oxford University Press. Please see the full study for a list of all other authors’ relevant financial disclosures.