No available methodologically 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. Lack of evidence clearly shows the need for well-conducted, controlled studies on this topic. 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.
Melatonin and agomelatine for preventing seasonal affective disorder
Kaminski-Hartenthaler, A., Nussbaumer, B., Forneris, CA., Morgan, L., Gaynes, BN., Sonis, JH., ... Gartlehner, G. (2015). Melatonin and agomelatine for preventing seasonal affective disorder. Cochrane Database of Systematic Reviews, 11, CD0211271. https://doi.org/10.1002/14651858.CD011271.pub2