Costs and cost-effectiveness of seasonal affective disorder treatment: Comparing light therapy, group cognitive -behavioral therapy, and their combination

Examining treatment costs and cost-effectiveness has become increasingly important in evaluating treatment programs. However, the cost-effectiveness of seasonal affective disorder (SAD) treatment has not been evaluated. Relative to the "best available" treatment (i.e., light therapy; LT), preliminary data suggest that a SAD-tailored, group cognitive-behavioral therapy (CBT) is equally efficacious during the acute treatment phase with less severe symptoms and lower recurrence rates during the subsequent winter. Here, the relative cost-effectiveness of CBT, LT, their combination (CBT+LT), and a minimal contact/delayed treatment control (MCDT) was determined. Participants with Major Depression, Recurrent with Seasonal Pattern were randomized to 1 of 4 6-week conditions: LT (90-min. of 10,000 lux/day), CBT (12 group sessions), CBT+LT, or a MCDT. Structured Interview Guide for the Hamilton Rating Scale for Depression-SAD Version (SIGH-SAD) remission rates and quality adjusted life years (QALY) derived from the Beck Depression Inventory 2nd Edition (BDI-II) served as measures of effectiveness. Treatment adherence was also assessed. Data from participants who were randomized to and completed the 6-week treatment phase were used for the post-treatment analysis (N = 59), and only the active treatment groups attended a 1-year winter follow-up visit (N = 39). Mental health provider rates from Antonuccio et al. (1997) were used to estimate treatment costs in the present study. Those rates were adjusted to represent 2003 dollars in the Washington, DC metro area. In general, all three treatments were significantly more effective than MCDT and similar in effectiveness to each other at post-treatment. At the 1-year follow-up, CBT and CBT+LT were similar in effectiveness to each other, and both were significantly more effective than LT. CBT was found to be the least expensive treatment with similar outcomes to LT at post-treatment and significantly more favorable outcomes than LT at 1-year follow-up. CBT+LT was found to be the most expensive treatment, and the effectiveness of CBT+LT was not significantly different from CBT. CBT had the lowest cost per QALY followed by LT. CBT+LT had the highest cost per QALY. The findings suggest that Rohan's group CBT for SAD holds promise as a cost-effective, stand-alone, treatment alternative to LT.