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How the "Chemical Imbalance" Metaphor Harms Patients

How we talk about depression affects our ability to heal.

Key points

  • People who think their depression comes from a chemical imbalance are more pessimistic about recovery.
  • They also tend to believe that medication is more useful than therapy.
  • Fortunately, there are better ways of talking about depression and the brain.
cottonbro studios/Pexels
Source: cottonbro studios/Pexels

The way we talk and think about mental illness is a profound ethical issue in its own right, similar to how we talk and think about race, sexual orientation, or gender identity.

Our careless use of metaphors can actually make people worse off.

Depression has long been framed as a "chemical imbalance"—a matter of too much or too little of various chemicals in the brain. Drugs like Prozac were long thought to improve people's lives by restoring these chemicals to their “correct” proportions.

Although the simplistic serotonin hypothesis of depression—the idea that depression stems from too little serotonin—has since fallen into clinical disfavor, chemical imbalance as a metaphor is alive and well, and it may be more harmful than we realize.

A Careless Metaphor

Starting in the 1980s, prominent psychiatrists, journalists, and medical brochures regularly referred to these chemical imbalances to describe the cause of depression. For example, a 2005 informational pamphlet, published by the American Psychiatric Association, informs us that medications can “correct imbalances in the levels of chemicals in the brain.”

Today, the metaphor is still prevalent in YouTube videos, among social workers, and even on some prominent medical websites. For example, MedlinePlus, an informational website hosted by the National Institutes of Health, claims that the antidepressant drug Imipramine works by “increasing the amounts of certain natural substances in the brain that are needed to maintain mental balance.”

The metaphor that the healthy brain exhibits just the right amounts and proportions of various chemicals, and that in the disordered brain, this chemical cocktail is askew, has for decades been an irresistible way to think and talk about mental illness.

Few psychologists, however, have studied the impact these metaphors have on the lives of depressed people or others who are labeled disordered. That's starting to change, as messaging about depression is now the target of a new scientific investigation.

Scientists Revisit the Metaphor

A symposium at the 2023 Association for Psychological Science (APS) convention, held last week in Washington, D.C., approached the chemical imbalance metaphor from multiple angles. It was entitled, “Beliefs about Chemical Imbalances, Genetics, and Emotions in Depression and Addiction: Relations with Treatment Attitudes and Self-Efficacy.”

It’s long been known that biological explanations for mental illness tend to be stigmatizing. Although they can reduce blame, they can also fuel the stigma that people with mental illnesses can be unpredictable and dangerous. They can also leave patients pessimistic about their chances of recovery. These speakers presented new data to give us a fuller picture of what’s at stake.

The first speaker, Briana Hay of the University of Michigan, gave preliminary evidence that the chemical imbalance message tends to limit the health choices of older Americans. The majority of older Americans in her sample were well aware of the “chemical imbalance” metaphor, which they’d acquired largely through media (TV and magazines, for example). In contrast, younger people are primarily exposed to the metaphor in the classroom.

Among older adults, those who believed that depression stems from a chemical imbalance were more likely to seek medication and less likely to seek therapy.

The second speaker, Elizabeth Kneeland, a professor of psychology at Amherst College, discussed how our beliefs about emotions can impact our well-being and health choices. People who see their emotions as malleable—subject to change over time—tend to experience less depression and are more inclined to seek therapy than people who see their emotions as relatively fixed and unchanging.

Kneeland didn't target the chemical imbalance metaphor directly. In my mind, however, her talk raised the disturbing prospect that the chemical imbalance metaphor might lead people to think that their low mood is more fixed and permanent than it really is.

The third speaker, Hans Schroder, a clinical psychologist and professor of psychiatry at the University of Michigan, presented evidence that there’s nothing stigmatizing about the mere idea that my depression has biological causes; after all, love, jealousy and grief have biological causes, but we don't think of them as disorders. Rather, the stigmatizing power of the chemical imbalance metaphor comes from its insinuation that something in your brain isn't working as it’s supposed to or as nature intended. The idea that one’s brain is somehow malformed or defective is what gives the chemical imbalance metaphor its sting.

The fourth speaker, Matthew Lebowitz, a professor of psychiatry at Columbia University, focused on addiction rather than depression. He showed that, at least among lay people, people who believe there’s a genetic explanation for addiction are more pessimistic about the value of psychotherapy—although interestingly, this link is not as strong among clinicians. (I served as commentator for the session.)

A New Direction?

If the chemical imbalance metaphor is harmful, how can we better communicate about depression?

One option is to drop the language of imbalances and simply speak of chemical differences. Brain chemistry impacts all of our emotions. Drugs, among other interventions, can change that chemistry. We can talk about chemical differences associated with depression without insinuating that in depression, one’s brain isn’t working as nature intended.

A more powerful alternative to the chemical imbalance legacy—as I discussed here—would be to frame depression not as a dysfunction, but as your brain's evolved signal that something in your life isn't working the way that it should. In the best of cases, depression is actually a healthy signal that something in my life simply demands more attention, whether it's a relationship, a career plan, my work/life balance, or a major life goal.

Preliminary evidence suggests that framing depression as a functional response to the trials of life can lead depressed people to feel more empowered and optimistic about feeling better.

Whichever direction we go, the way we publicly talk about depression should be informed by the best available evidence about what kind of message is most likely to heal.

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