This article by Christopher Lane has been published in Psychology Today. It begins:
“Almost as soon as it was floated in 1965 by Harvard psychiatrist Joseph Schildkraut, the serotonin hypothesis of depression—reduced and simplified by pharma marketing to the ‘chemical imbalance’ theory of depression and anxiety—has been subject to critical research and found wanting.
The poor standing of the hypothesis in the scientific literature, however, barely dented its afterlife in textbooks, across clinical and treatment settings, and on mental health apps and websites. Nor has it dispelled the continued use of the phrase as ‘shorthand’ between doctors and patients and in everyday settings, including for quite different mental states and conditions.
The ‘Chemical Imbalance’ Metaphor Takes Root
Revisiting the history of this controversy raises several still-relevant details. In December 2005, as advertising for SSRI antidepressants flooded American magazines, talk shows, and network TV, the result of multibillion-dollar campaigns pitched in this case directly to consumers, Florida-based professors and researchers Jeffrey Lacasse and Jonathan Leo asked pointedly in PLoS Medicine, ‘Are the claims made in SSRI advertising congruent with the scientific evidence?’
The answer in ‘Serotonin and Depression: A Disconnect Between the Advertisements and the Scientific Literature,’ their well-researched article, was a resounding no. The resulting ‘incongruence,’ they determined, was ‘remarkable and possibly unparalleled.’ …”
You can read more from here.