The Effect of Melatonin on Sleep Quality, Anxiety, and Depression in Patients with Primary Breast Cancer Undergoing Adjuvant Chemotherapy Type: A Randomized, Double-Blind, Placebo-Controlled Trial

This study aimed to evaluate the effect of melatonin on sleep Quality, anxiety, and depression in the patients with primary breast cancer undergoing adjuvant chemotherapy in a double-blind, placebo-controlled trial. Forty patients with stage I-III breast cancer were allocated randomly to the intervention and control groups. The intervention group received 6 mg/day/6 months. At baseline, middle and end of chemotherapy, patients were evaluated using Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), Hospital Anxiety, and Depression Scale (HADS) questionnaires, respectively. Melatonin administration resulted in significant improvements in sleep latency (1.50 ± 1.04,1.28 ± 1.02,1.00 ± 1.08, P = 0.001), sleep efficiency (1.11 ± 1.08, 0.83 ± 1.15, 0.56 ± 0.92, P = 0.003), and total Pittsburgh Sleep Quality Index scores (8.39 ± 4.63, 7.56 ± 4.41, 6.50 ± 3.71, P = 0.003) when compared to the placebo group throughout the three phases of chemotherapy. Importantly, no statistically significant differences were noted during the Adriamycin phase of chemotherapy. In contrast, during the Taxol phase, the melatonin showed a statistically significant improvement in anxiety levels (7.33 ± 4.01 to 5.67 ± 0.88, P = 0.077) and overall PSQI scores (8.39 ± 4.62 to 9.13 ± 4.96, P = 0.015). These results indicate that melatonin may be a promising therapeutic option for addressing sleep disturbances in breast cancer patients.