In their article, Serotonin and Depression: A Disconnect between the Advertisements and the Scientific Literature, authors Lacasse and Leo pose a question at the end of their preface: “The pertinent question is: are the claims made in SSRI advertising congruent with the scientific evidence?” However, the authors failed to respond in a fair and balanced manner to their own question. Instead, they chose to do what they accuse pharmaceutical manufacturers of doing, providing a limited scientific evidentiary basis to suit their needs. Unfortunately, the question that they chose to answer was: “Can we find flaws in the serotonin or monoamine hypothesis of depression sufficient to discredit those who would argue it as a basis for explaining the mechanism of drug action or a treatment for depression?” That is something altogether different. In their response to that question, they succeeded.

This is especially disconcerting to my associates and me who continue to make small attempts to illuminate, in the peer-reviewed medical literature, authors and their published conclusions whose works---often pharmaceutically-funded clinical research--- may be more marketing than science.

I want to provide a simple example, often used before, to illustrate my point. A glass of milk that was sitting on a table in an otherwise empty room has just been spilled. The only person who was in the room before the milk was spilled and who exited the room after the milk was spilled was a ten-year old boy, Johnny. Johnny’s mother looks in the room after Johnny exits and exclaims, “Johnny, you spilled the milk.” Despite Johnny’s insistence that he didn’t do it, his mother is convinced that he did. “Johnny, the glass of milk was upright before you went in, no one else has been in the room, after only two minutes in the room, you came out and the milk was already spilled. You even have milk on your hands! You did it, all the evidence points to you. You are grounded.” Does that seem plausible? Perhaps. Trouble is, the family cat was in the room all along, is still in the room, likes milk and has milk in his belly from recent ingestion.

Analogously, finding evidence that exclusively supports an argument against sertraline or the monoamine hypothesis of depression by ignoring the contrarian evidence that argues in the opposite direction is bad science… because it is not science. It is just polemic that serves a very different purpose.

That’s exactly what Lacasse and Leo did and what PLoS validated by publishing their one-sided work. There are articles that do demonstrate a link between serotonin and depression that were left out of the Lacasse and Leo article. Oquendo, as one example, reviews many of the articles that support the serotonin hypothesis in an article published in Clinical Neuroscience Research. (1)

Both extremes in publishing and media are bad: When pharmaceutical companies publish advertisements and media that showcase limited and incomplete findings without providing a fair and balanced approach, they mislead doctors and healthcare consumers. Likewise, when anti-pharmaceutical writers marginalize fact-gathering and science to support conclusionary premises (“pharmaceutical companies don’t tell us the truth about drugs”), they perform the same disservice to doctors and healthcare consumers by offering their own biased, incomplete and misleading conclusions.


Stefan P. Kruszewski, MD
Steven G. Klotz, MD


1. Oquendo M, Neuroimaging findings in major depression, suicidal behavior and aggression. Clinical Neuroscience Research 2001 Nov; 1(5): 377-380.