Seasonal Affective Disorder and Its Prevention by Anticipatory Treatment with Bupropion XL

Background Seasonal affective disorder (SAD) can cause significant distress and impairment. No antidepressant studies have previously attempted to prevent the onset of autumn-winter depression. Methods Three prospective, randomized, placebo-controlled prevention trials were conducted on 1042 SAD patients, enrolled in autumn and treated while still well, across the northern US and Canada. Patients received either bupropion XL 150-300 mg or placebo daily by mouth from enrollment until spring and were then followed off medications for 8 additional weeks. Primary efficacy variables were end-of-treatment depression-free rates and survival distributions of depressive recurrence. Results Despite a reported average of 13 previous seasonal depressive episodes, almost 60% of patients had never previously been treated for depression. Major depression recurrence rates during the three studies for bupropion XL and placebo groups were 19% versus 30% (p = 0.026), 13% versus 21% (p = 0.049), and 16% versus 31%; yielding a relative risk reduction across the three studies of 44% for patients taking bupropion XL. Survival analyses for depression onset also favored bupropion XL over placebo (p = .081, .057, and <.001). Conclusions It is possible to prevent recurrence of seasonal major depressive episodes by beginning bupropion treatment early in the season while patients are still well.