RESUMEN
We conducted a systematic review and meta-analysis of randomised controlled trials (RCTs) evaluating the effects of melatonin intake on depression and anxiety in postmenopausal women. To identify RCTs examining the effect of melatonin supplementation on depression and anxiety scores in postmenopausal women, a comprehensive electronic search was conducted via the Cochrane Central Register of Controlled Trials, Science direct, Google Scholar, PubMed, Medline, Scopus and Web of Science databases using the keywords ("melatonin" OR "N-acetyl serotonin") AND ("menopause" OR "climacteric") AND ("depression" OR "anxiety"). The search strategy was applied to articles published between January 2000 and April 2023. The Cochrane tool was used to evaluate the bias risk in RCTs. For the meta-analysis, fixed effect models and random effect models were employed based on heterogeneity. Preferred Reporting Items for Systematic Reviews and Meta-Analysis in Our Study guidelines were followed. Five RCTs were included in the study, with a total sample size of 441 (experimental: 227 and control: 214). When the effect of melatonin use on depression in menopausal women was analysed, it was found that melatonin significantly reduced menopausal depression (SMD - 0.166, CI = - 0.288/ - 0.045, p < 0.05). When the effect of melatonin use on anxiety in postmenopausal women was analysed, it was found that melatonin significantly improved menopausal anxiety (SMD - 0.806, CI = 1.491/ - 0.120, p < 0.05). Melatonin is promising as a potential treatment to help depression and anxiety in the postmenopausal period. More high-quality studies are needed to determine their safety.