Effect of Melatonin on Depressive Symptoms and Anxiety in Patients Undergoing Breast Cancer Surgery: A Randomised, Double-Blind, Placebo Controlled Trial, Hansen, M V et al Breast Cancer Research and Treatment 2014 No 145 pp 683-695
This study looked at 54 patients undergoing breast surgery for cancer who did not have depression at baseline. The incidence of depression in the placebo group at three months was 45% and the incident of depression in the group treated with Melatonin 6mg nocte for three months was 11%. The number needed to treat was 3.0.
Comment:
This is the first study showing Melatonin preventing depression in a group at high risk of developing it. The number needed to treat of 3.0 is profound.
If replicated, this would be a valuable means of preventing depression in high risk individuals and further studies could be conducted in trauma settings for example.
The exact mechanism via which Melatonin reduced the risk of depression developing is unclear as there have been few studies in this area to date.
At least in females undergoing breast cancer surgery, there may be a role for considering prophylactic use of Melatonin.