Overall , both forms of preventive light therapy reduced the incidence of SAD numerically compared with no light therapy .
BACKGROUND Seasonal affective disorder ( SAD ) is a seasonal pattern of recurrent major depressive episodes that most commonly occurs during autumn or winter and remits in spring .
The prevalence of SAD ranges from 1.5 % to 9 % , depending on latitude .
The predictable seasonal aspect of SAD provides a promising opportunity for prevention .
This review - one of four review s on efficacy and safety of interventions to prevent SAD - focuses on light therapy as a preventive intervention .
Light therapy is a non-pharmacological treatment that exposes people to artificial light .
Mode of delivery ( e.g. visors , light boxes ) and form of light ( e.g. bright white light ) vary .
OBJECTIVES To assess the efficacy and safety of light therapy ( in comparison with no treatment , other types of light therapy , second-generation antidepressants , melatonin , agomelatine , psychological therapies , lifestyle interventions and negative ion generators ) in preventing SAD and improving patient-centred outcomes  among adults with a history of SAD .
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 prospect i ve , r and omized , 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
Overall , both forms of preventive light therapy reduced the incidence of SAD numerically compared with no light therapy .
BACKGROUND Seasonal affective disorder ( SAD ) is a seasonal pattern of recurrent major depressive episodes that most commonly occurs during autumn or winter and remits in spring .
The prevalence of SAD ranges from 1.5 % to 9 % , depending on latitude .
The predictable seasonal aspect of SAD provides a promising opportunity for prevention .
This review - one of four review s on efficacy and safety of interventions to prevent SAD - focuses on light therapy as a preventive intervention .
Light therapy is a non-pharmacological treatment that exposes people to artificial light .
Mode of delivery ( e.g. visors , light boxes ) and form of light ( e.g. bright white light ) vary .
OBJECTIVES To assess the efficacy and safety of light therapy ( in comparison with no treatment , other types of light therapy , second-generation antidepressants , melatonin , agomelatine , psychological therapies , lifestyle interventions and negative ion generators ) in preventing SAD and improving patient-centred outcomes  among adults with a history of SAD .