Efficacy of Melatonin in Alleviating Radiotherapy-Induced Fatigue, Anxiety, and Depression in Breast Cancer Patients: A Randomized, Triple-Blind, Placebo-Controlled Trial

Background: This trial evaluated the efficacy of melatonin versus placebo in alleviating radiotherapy-induced fatigue, anxiety, and depression in breast cancer patients. Methods and materials: This randomized, triple-blind, parallel-group, single-center clinical trial was conducted in the radiation oncology department of Namazi Hospital in Shiraz, Iran. Eligible breast cancer patients scheduled for adjuvant radiotherapy were randomly assigned to receive either 20 mg oral melatonin daily or a placebo. All participants underwent conventional radiotherapy (50 Gy total, delivered as 2 Gy per day). Patients in the melatonin group received the intervention starting on the first day of radiotherapy and continuing until treatment completion. Assessments were performed at baseline and 1 week after the intervention using the Multidimensional Fatigue Inventory and Beck’s Depression and Anxiety checklists. Data were analyzed using SPSS version 22 with a significance level set at P < .05. Results: Both groups (n = 50 each) had comparable baseline characteristics. Baseline MFI fatigue ( P = .06), Beck Anxiety Inventory ( P = .5), and Beck Depression Inventory ( P = .9) scores showed no significant differences between groups. Post-intervention, the melatonin group had significantly lower scores than the placebo group (Mann–Whitney U test, P < .001 for all): MFI fatigue (median: 42.5 vs 55), Beck Anxiety Inventory (median: 28.5 vs 38), and Beck Depression Inventory (median: 29 vs 38). In the placebo group, changes were minimal: MFI fatigue scores were nearly unchanged (median: 56 vs 55), with no significant differences in Beck Anxiety Inventory (median: 38 vs 38, P = .08) or Beck Depression Inventory scores (median: 38 vs 38, P = .3). Within the melatonin group, the Friedman test showed significant reductions from baseline to post-intervention in MFI fatigue (median: 61-42.5), Beck Anxiety Inventory (median: 38-28.5), and Beck Depression Inventory scores (median: 38.5-29; P < .001 for all). Conclusion: Melatonin administration during radiotherapy significantly alleviated fatigue, anxiety, and depression in breast cancer patients.