Researchers have been warning for 20 years that the most profitable psychiatric drugs in history are marketed on claims that have no scientific backing.

If you've ever seen a commercial for Zoloft, Paxil, or Prozac, you've probably heard the pitch: depression is caused by a "chemical imbalance" in your brain, and these drugs work by "correcting" that imbalance. This was the pivot from the prior "serotonin deficiency" marketing slogan that was too risky to continue pushing due to the severe lack of credible evidence to support it. 

As with many other fraudulent claims used to push chemicals to unsuspecting civilians (think cholesterol and heart disease, for example), consciousness researchers voice concerns that largely go unnoticed.

An example of this was a comprehensive 2005 analysis published in PLoS Medicine that exposed one of the most successful marketing campaigns in pharmaceutical history. Researchers Jeffrey Lacasse and Jonathan Leo systematically examined the scientific evidence behind the "serotonin hypothesis" of depression and compared it to what drug companies were telling consumers. What they found should concern anyone who's been prescribed an antidepressant or knows someone who has.

Study Findings

The researchers discovered a shocking disconnect between pharmaceutical marketing and actual science. Despite decades of research and billions in funding, scientists have never found evidence that depression is caused by low serotonin levels. The study authors compiled quotes from leading neuroscientists and psychiatrists – including many who support antidepressant use – all stating the same thing: there's no proof of serotonin deficiency in depression.

One Stanford psychiatrist who won awards for serotonin research put it bluntly: "I never saw any convincing evidence that any psychiatric disorder, including depression, results from a deficiency of brain serotonin."

The research reveals multiple failed attempts to prove the serotonin theory:

Studies comparing serotonin levels in depressed versus healthy people produced inconsistent, contradictory results

Experiments that deliberately lowered serotonin levels in volunteers didn't cause depression

Massive doses of serotonin-boosting supplements failed to cure depression