The chemical imbalance theory of depression is dead – but that doesn’t mean antidepressants don’t work

‘We still don’t really know how or why antidepressants work. The brain is a complex organ.’ Photograph: Zerilli Media/Alamy

The chemical imbalance theory of depression is well and truly dead. A paper by Joanna Moncrieff and colleagues, longtime critics of the effectiveness of antidepressants, has caused a splash. The paper provides a summary of other summaries that confirm there is no evidence to support the idea that depression is caused by disturbance of the brain’s serotonin system.

They have done us a favour by corralling the evidence that says as much, even if we knew this to be the case.