Preventing depression in breast cancer patients after surgery; can melatonin help?

The authors aimed to determine the effectiveness of melatonin (Circadin) to treat women with breast cancer who have depressive symptoms.

Depression or depressive symptoms (anxiety, sleep disturbance, fatigue, pain and dizziness) can occur in up to 50% of women with breast cancer. This can occur following surgery and can reduce a patients quality of life and overall recovery.

While there are various known anti-depressant drugs available, the effects of melatonin as an anti-depressant has not been well studied. Melatonin is a hormone that regulates sleep and waking cycles in the body. 

The aim of this study was to evaluate the effects of melatonin on the risk of depression symptoms in women with breast cancer.

A total of 54 patients were evaluated for this study, all of whom had or were scheduled to receive either a lumpectomy (removal of the tumor and some surrounding tissues- breast remains intact) or a mastectomy (removal of the tumor and entire breast). Out of these women, 28 were allocated to a course of melatonin while 26 were allocated to placebo tablets (a substance that has no therapeutic effect).

Overall, there was a significant difference between the two treatment groups. Melatonin reduced the risk of depressive symptoms after breast cancer surgery by 75%. Only 11% of the melatonin treatment group compared to 45% of the placebo group developed depressive symptoms. Melatonin proved to have early effects as there was a significant difference between the two groups after only three weeks of recovery.

Side effects did not differ greatly between groups. 27% of those on placebo experienced headaches compared to 10% of those taking melatonin. 7% of those taking placebo experienced dizziness compared to 14% of those taking melatonin. None of the placebo group experienced a numb or tingling sensation in their mouth/arms/legs compared to 10% of those receiving melatonin. 

The authors concluded that melatonin may be effective in reducing the risk of depressive symptoms in women with breast cancer. 

This study contained a small group of women.

If you feel you are developing depressive symptoms during the course of your breast cancer treatment, you should seek advice from your doctor.