https://www.independent.co.uk/news/health/depression-serotonin-symptoms-evidence-study-b2127229.html
A review of existing studies by University College London (UCL) found that depression is not likely to be caused by a chemical imbalance and asked patients to consider other treatments over antidepressant medication.
However, other medical experts are urging people not to stop taking their antidepressants because of the findings and argue they are effective in treating depression.