Dr. Mark Horowitz, MBBS PhD is a training psychiatrist and Clinical Research Fellow in Psychiatry North East London NHS Foundation Trust (NELFT) and an Honorary Clinical Research Fellow at UCL. He runs the Psychotropic drug Deprescribing Clinic in North East London NHS Foundation Trust. Mark completed a PhD in the neurobiology of depression and the action of antidepressants at the Institute of Psychiatry, Psychology and Neuroscience at King’s College London.
Dr. Horowitz is an Associate Editor of the journal Therapeutic Advances in Psychopharmacology. He co-authored the recent Royal College of Psychiatry guidance on ‘Stopping Antidepressants’, and his work has informed the recent NICE guidelines on safe tapering of psychiatric medications. He has written several papers about safe approaches to tapering psychiatric medications including publications in The Lancet Psychiatry, JAMA Psychiatry and Schizophrenia Bulletin.
Review: “The Myth of Low-Serotonin & Antidepressants” – Mark Horowitz
In this clear and courageous talk, training psychiatrist and researcher Mark Horowitz dismantles one of psychiatry’s most profitable myths: that depression is caused by a “chemical imbalance” of low serotonin. Horowitz shows how this idea, never supported by evidence, was deliberately propagated by drug companies in the 1990s and 2000s to market SSRIs as a neat, scientific fix — much like antibiotics for an infection. Decades of studies (including his own) confirm there is no consistent link between low serotonin and depression, whether measured in blood, spinal fluid, brain scans, genes, or dietary depletion.
Yet the myth persists, sustaining massive prescribing rates — over 100 million people worldwide, one in six to one in eight adults in Western countries annually — often for people with no evidence-based indication. Horowitz explains that antidepressants do not reverse any underlying disease but act more like alcohol for social anxiety: they superimpose drug-induced changes (emotional numbing, sedation, or activation) that can wear off, leading to tolerance, “antidepressant poop-out,” and severe withdrawal symptoms easily mistaken for relapse. These symptoms — dizziness, brain zaps, anxiety, depression, depersonalization — can last months or longer, yet official guidance still downplays them. Hyperbolic tapering offers a safer path, but psychiatric education remains woefully inadequate on stopping these drugs.
This presentation aligns squarely with Per Lanterna’s lantern: psychiatry as big business first, science second. The chemical-imbalance narrative is textbook pharma marketing dressed up as medicine, keeping patients as repeat customers while real social and personal causes of distress are sidelined. No causes found. No cures delivered. Just more pills.
Horowitz, himself a long-term user now tapering, delivers a rare insider critique without shaming those who feel helped. His message is essential: people deserve informed consent, not lifelong dependence on a myth. Highly recommended viewing for anyone prescribed antidepressants or questioning psychiatry’s chemical solutions.
(Per Lanterna continues to hold the lantern high on these issues — more light is urgently needed.)
Chemical imbalance – psychiatry as a pharma marketing tool
