Little evidence that chemical imbalance causes depression, UCL scientists find

Scientists have called into question the widespread use of antidepressants after a major review found “no clear evidence” that low serotonin levels are responsible for depression.

Prescriptions for antidepressants have risen dramatically since the 1990s, with one in six adults and 2% of teenagers in England now being prescribed them. Millions more people around the world regularly use antidepressants.

“Many people take antidepressants because they have been led to believe their depression has a biochemical cause, but this new research suggests this belief is not grounded in evidence,” said the study's lead author, Joanna Moncrieff, a professor of psychiatry at University College London and consultant psychiatrist at North East London NHS foundation trust.

“It is always difficult to prove a negative, but I think we can safely say that after a vast amount of research conducted over several decades, there is no convincing evidence that depression is caused by serotonin abnormalities, particularly by lower levels or reduced activity of serotonin.