AUTHORS ' CONCLUSIONS No available method ologically sound evidence indicates that melatonin or agomelatine is or is not an effective intervention for prevention of SAD and improvement of patient-centred outcomes among adults with a history of SAD .
A well-conducted RCT of melatonin or agomelatine for prevention of SAD would assess the comparative benefits and risks of these interventions against others currently used to treat the disorder
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 in the United States ranges from 1.5 % to 9 % , depending on latitude .
The predictable seasonal aspect of SAD provides a promising opportunity for prevention .
This is one of four review s on the efficacy and safety of interventions to prevent SAD ; we focus on agomelatine and melatonin as preventive interventions .
OBJECTIVES To assess the efficacy and safety of agomelatine and melatonin ( in comparison with each other , placebo , second-generation antidepressants , light therapy , psychological therapy or lifestyle interventions ) in preventing SAD and improving patient-centred outcomes among adults with a history of SAD .
Effects of morning phototherapy on circadian markers in seasonal affective disorder.
BACKGROUND The suppression of melatonin by light at 00.30 hours has been shown to be greater in winter than in summer on patients with seasonal affective disorder ( SAD ) but not in matched normal controls . METHOD In this study 12 patients with SAD and 12 matched normal controls were exposed to morning light therapy in the winter .  Melatonin profiles and sensitivity to light were measured before and after treatment . RESULTS The SAD but not the normal group showed a phase advance of melatonin rhythms in response to phototherapy . There was an association between phase position and phase shift in the SAD but not in the normal group . CONCLUSIONS There may be instability of circadian rhythms in SAD mediated by a high-amplitude phase response curve , rather than a fixed phase abnormality as had been previously suggested . This instability may be secondary to impaired serotoninergic function in the afferent pathways to the suprachiasmatic nuclei
AUTHORS ' CONCLUSIONS No available method ologically sound evidence indicates that melatonin or agomelatine is or is not an effective intervention for prevention of SAD and improvement of patient-centred outcomes among adults with a history of SAD .
A well-conducted RCT of melatonin or agomelatine for prevention of SAD would assess the comparative benefits and risks of these interventions against others currently used to treat the disorder
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 in the United States ranges from 1.5 % to 9 % , depending on latitude .
The predictable seasonal aspect of SAD provides a promising opportunity for prevention .
This is one of four review s on the efficacy and safety of interventions to prevent SAD ; we focus on agomelatine and melatonin as preventive interventions .
OBJECTIVES To assess the efficacy and safety of agomelatine and melatonin ( in comparison with each other , placebo , second-generation antidepressants , light therapy , psychological therapy or lifestyle interventions ) in preventing SAD and improving patient-centred outcomes among adults with a history of SAD .