Joanna Moncrieff and Mark Horowitz, part of the group of authors conducted this study.

AuthorsJoanna MoncrieffRuth E. CooperTom StockmannSimone AmendolaMichael P. Hengartner & Mark A. HorowitzPublicationMolecular Psychiatry (2022)Cite this article

Date: 20 July 2022

This article is clear summary of the scientific facts regarding the serotonin theory of depression, and how this theory no longer holds up to current evidence.

It is science rich, lots of statistics, medical terms and microbiology. The message does not change however.

The summary of their findings“The main areas of serotonin research provide no consistent evidence of there being an association between serotonin and depression, and no support for the hypothesis that depression is caused by lowered serotonin activity or concentrations. Some evidence was consistent with the possibility that long-term antidepressant use reduces serotonin concentration.”

This review also suggests that the “huge research effort based on the serotonin hypothesis has not produced convincing evidence of a biochemical basis to depression. This is consistent with research on many other biological markers. We suggest it is time to acknowledge that the serotonin theory of depression is not empirically substantiated.”

The idea that depression is the result of abnormalities in brain chemicals, particularly serotonin (5-hydroxytryptamine or 5-HT), has been influential for decades.

What is more concerning is 80% or more of the general public now believe it is an established fact that depression is caused by a ‘chemical imbalance’. Many general practitioners also subscribe to this view and popular websites commonly cite this theory.

What does this mean for those of us who do have depression episodes and experiences? We need to be aware that anti depression medication does not always deliver the results we seek. They may be helpful for some – not because the SSI medication is helping your depressed behaviours, but because it is likely to be changing something else in your body.

We know depression experiences are not caused by any single “thing” or event. It is a result of many contributing factors. It makes sense then, to treat depression behaviours and experiences with a combination of treatments – psychotherapy, hypnotherapy, mindfulness. Only agree to use SSI medication if your doctor feels that it may support other symptoms in your history. Trial some therapy – in whatever form you choose, and then only resort to anti depressants if both you and your doctor agree it may be helpful.