Chemically Imbalanced

Why the Chemical Imbalance Story Spread

Depression and anxiety are now widely treated as medical illnesses caused by a chemical imbalance in the brain, usually described as too little serotonin. That explanation became so common that many people came to see it as settled science. It appeared in doctors’ offices, public campaigns, news coverage, and drug advertisements, until it felt like simple fact. Yet the evidence for it was never solid.

A major cultural shift happened between the 1980s and the 2000s. Sadness had once been more commonly understood as a response to life events such as loss, loneliness, conflict, or disappointment. Joanna Moncrieff remembers going through a period of deep distress as a teenager and recovering through changes in her surroundings and relationships, not through medication. Later, many people in similar situations were told instead that their brains were malfunctioning and needed drugs.

This new story did more than explain distress. It changed how people saw themselves. Mark Horowitz, after years of bullying and isolation, was told he had a brain disorder and was prescribed medication after medication. Rather than restoring him, the drugs brought fatigue, memory problems, and severe withdrawal when he tried to stop. His experience shows how a temporary human crisis can become a long medical journey once it is framed as a chemical defect.

The spread of this theory served practical interests. Psychiatry gained the appearance of having precise medical treatments, and drug companies gained a huge market. After older tranquilizers became tainted by concerns about dependence, antidepressants were promoted as something entirely different: not sedatives or emotional suppressants, but targeted medicines correcting a biological fault. That rebranding helped turn ordinary suffering into a reason for long-term prescribing.

The result was an enormous rise in antidepressant use, even though the chemical imbalance claim remained unproven. People were encouraged to think of themselves as patients with faulty brains rather than individuals reacting to difficult lives. That shift shaped treatment, public attitudes, and personal identity. It also pushed attention away from the conditions that so often drive despair: trauma, poverty, overwork, isolation, and lack of meaning.