Joanna Moncrieff. Chemically Imbalanced: The Making and Unmaking of the Serotonin Myth. Flint Books; 2024. Pages: 336, INR 1545 (paperback). ISBN: 9780750999336

When my husband Woody died by suicide in 2003, just five weeks after being prescribed Zoloft (Sertraline) for insomnia, my entire world blew up. I wasn’t a doctor or a policy expert — I was his wife. But that moment launched me into a fight I never asked for: a two-decade journey through litigation, public health advocacy, and the deeply flawed systems of drug safety oversight. My professional background in advertising and marketing gave me a different perspective, showing me how narratives are crafted, repeated, and sold to the public. The chemical imbalance theory was not just a medical idea; it was a marketing strategy, repeated until it became “truth.”

Joanna Moncrieff’s Chemically Imbalanced is both validating and unsettling. Moncrieff, a respected psychiatrist and professor at University College London, meticulously exposes how the serotonin hypothesis of depression gained prominence without robust scientific support. Her 2022 umbrella review in Molecular Psychiatry concluded there was no consistent evidence linking low serotonin to depression [1]. Despite criticism, she doubles down here, illustrating clearly how the chemical imbalance narrative became entrenched in the mental health industry through strategic marketing rather than definitive science. She points, for example, to the oft-repeated analogy that depression is “like diabetes” and antidepressants are “like insulin” — a simple, memorable comparison that originated in pharmaceutical PR campaigns, not peer-reviewed evidence.

Moncrieff draws from a wide range of sources — from re-analyses of landmark trials to marketing briefs, regulatory filings, and patient accounts — weaving them into a narrative that’s as accessible as it is unsettling. She is at her sharpest when unpacking how subtle language choices, repetition, and selective data reporting shaped not only public opinion but also clinical guidelines. By showing how marketing claims were seamlessly integrated into medical education, patient leaflets, and public health messaging, she demonstrates the ease with which medical “truths” can be manufactured and defended long after the evidence collapses. This level of detail makes the book not just a history of a flawed theory, but an exposé of the machinery that sustains it.

As someone who reviewed internal pharmaceutical documents during my litigation against Pfizer, I’ve seen firsthand the very dynamics Moncrieff outlines. Clinical trials frequently showed minimal benefit over placebo, with significant risks like suicidality or withdrawal, deliberately downplayed or hidden. The public, however, received a different message: depression was a simple chemical deficiency fixable by a pill. Moncrieff revisits notorious cases such as GlaxoSmithKline’s Study 329, where trial outcomes for Paxil (Paroxetine) in adolescents were manipulated to hide increased suicidality and lack of efficacy [2]. This is an example that illustrates systemic, not isolated, malpractice.

Beyond the scientific critique, Moncrieff addresses the cultural shift towards medicalising normal human emotions like grief, anxiety, sadness into “disorders” requiring pharmaceutical solutions. Even my doctor tried to offer me an antidepressant for my grief after my husband’s death. This “creeping medicalisation” has resulted in soaring diagnoses without corresponding improvement in outcomes. Importantly, Moncrieff is not anti-medication; she advocates for transparency, informed consent, and a more nuanced understanding of psychiatric drugs’ effects, calling for clinicians and regulators to prioritise patient wellbeing over marketing narratives.

For me, reading Chemically Imbalanced was both an affirmation and a reminder of why I continue this work more than twenty years after Woody’s death. The book makes plain that what’s at stake is not just academic accuracy, but the lived realities of millions of people prescribed psychiatric drugs based on incomplete or misleading narratives. We are seeing this play out in real time today, as these arguments are defended and repeated by politicians, further entrenching myths that should have been dismantled long ago. It challenges us to ask harder questions of our health systems, our regulators, and ourselves, and to imagine a future where care is grounded in honesty, humility, and genuine human connection. That is a conversation long overdue.

Author: Kim Witczak (hello@kimwitczak.com), Drug Safety Advocate, Minneapolis, Minnesota, USA.

Conflict of Interest: The author has acted as a Consumer Representative on the US FDA Psychopharmacologic Drugs Advisory Committee.

Funding: None

To cite: Witczak K. Chemically imbalanced: When marketing masquerades as science. Indian J Med Ethics. Published online first on November 12, 2025. DOI: 10.20529/IJME.2025.085

Submission received: May 28, 2025

Submission accepted: October 23, 2025

Manuscript Editor: Sanjay A Pai

Copyright and license

©Indian Journal of Medical Ethics 2025: Open Access and Distributed under the Creative Commons license (CC BY-NC-ND 4.0), which permits only noncommercial and non-modified sharing in any medium, provided the original author(s) and source are credited.