Some 2,000 years ago, the Ancient Greek scholar Hippocrates argued that all ailments, including mental illnesses such as melancholia, could be explained by imbalances in the four bodily fluids, or “humors.” Today, most of us like to think we know better: Depression—our term for melancholia—is caused by an imbalance, sure, but a chemical imbalance, in the brain.
This explanation, widely cited as empirical truth, is false. It was once a tentatively-posed hypothesis in the sciences, but no evidence for it has been found, and so it has been discarded by physicians and researchers. Yet the idea of chemical imbalances has remained stubbornly embedded in the public understanding of depression.
Prozac, approved by the US Food and Drug Administration 30 years ago today, on Dec. 29, 1987, marked the first in a wave of widely prescribed antidepressants that built on and capitalized off this theory. No wonder: Taking a drug to tweak the biological chemical imbalances in the brain makes intuitive sense. But depression isn’t caused by a chemical imbalance, we don’t know how Prozac works, and we don’t even know for sure if it’s an effective treatment for the majority of people with depression.
One reason the theory of chemical imbalances won’t die is that it fits in with psychiatry’s attempt, over the past half century, to portray depression as a disease of the brain, instead of an illness of the mind. This narrative, which depicts depression as a biological condition that afflicts the material substance of the body, much like cancer, divorces depression from the self. It also casts aside the social factors that contribute to depression, such as isolation, poverty, or tragic events, as secondary concerns. Non-pharmaceutical treatments, such as therapy and exercise, often play second fiddle to drugs.
In the three decades since Prozac went on the market, antidepressants have propagated, which has further fed into the myths and false narratives we tell about mental illnesses. In that time, these trends have shifted not just our understanding, but our actual experiences of depression.