Serotonin Theory of Depression: Landmark Review Challenges Chemical Imbalance Model
Is depression caused by low serotonin?
No. A comprehensive umbrella review of 17 studies found no consistent evidence linking depression to lowered serotonin concentration or activity. The review examined six major areas of serotonin research and found no support for the hypothesis that depression is caused by serotonin deficiency, challenging decades of accepted theory.
The review found that evidence across multiple research domains consistently failed to support the serotonin theory, with some findings suggesting long-term antidepressant use may actually reduce serotonin concentration rather than increase it.