“Chemical imbalance” is a long discarded hypothesis 1 that low serotonin-level causes depression. Modern researches found that depression is not generally linked with serotonin deficiency 2.

This idea was heavily pushed by drug companies to sell serotonin-selective reuptake inhibitor (SSRI) compounds 1.

This explanation also has the stigmatizing effect by insinuation that something in the brain isn’t working as it’s supposed to or as nature intended. Further, it encourage a fixed mindset on emotion, which prevent people from seeking therapy. 3

References

Footnotes

  1. A Popular Theory About Depression Wasn’t “Debunked” by a New Review | Technology Networks (note) 2

  2. The serotonin theory of depression: a systematic umbrella review of the evidence | Molecular Psychiatry

  3. How the “Chemical Imbalance” Metaphor Harms Patients | Psychology Today (note)