In a study comparing light therapy versus cognitive behavioral therapy (CBT) for the treatment of seasonal affective disorder (SAD), University of Vermont researcher Kelly Rohan found that CBT may be most effective at preventing future episodes of the disorder.
Rohan randomized 69 people with SAD, a form of depression which occurs during the fall and winter months, into one of four groups: light therapy, cognitive behavior therapy, a combination of the two or a wait-list control group. She then surveyed the participants the following winter to determine how well the interventions had prevented a recurrence of the disorder.
Rohan determined that only 7% of the group treated with CBT had a recurrence, compared to 36.7% of those treated with light therapy. The recurrence in the combination group was 5.5%. In addition, the severity of the depression experienced by those who had CBT was less than that experienced by either the light therapy group or the combination group.
Why did the light therapy group do so poorly the following year? According to Rohan, long-term compliance with this type of treatment is rare. It requires sitting in front of a light box for 30 minutes a day during a time when people may not be feeling their best. In fact, in this particular study, only four participants opted to use the light box the second winter.
Does this mean that light therapy is not a good treatment for SAD? Not necessarily. What it does mean is that even if a treatment is effective, you won't benefit from it, if, due to your illness, you cannot summon the motivation to use it.
Rohan's goal, she said, is to develop effective treatments with good compliance rates in order to give patients better long-term outcomes.
The study appeared in the September issue of Behavior Therapy.
