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Nuances, Narratives, and the “Chemical Imbalance” Debate

Nuances, Narratives, and the “Chemical Imbalance” Debate

Chemical Imbalance Debate
Religions, cultures, and political groups all have their narratives—usually favorable or flattering accounts of their origins and beliefs. But narratives are not the same as truths, and usually lack the nuances of truth, which is rarely black or white. To see how this applies to psychiatry, try answering the question: Which one of the following statements best characterizes the American Psychiatric Association’s 2005 position on the causes of mental illness?

1. All mental illness is caused by specific and identifiable chemical imbalances in the brain.

2. The most serious mental illnesses, such as schizophrenia and major depression, are caused by specific chemical imbalances.

3. Chemical imbalances of some sort cause some mental illnesses.

4. The exact causes of mental disorders are unknown.

Now, if you were to give credence to a recent online polemic posing as investigative journalism, you would probably choose the first or second statement.1 In the narrative of the antipsychiatry movement, a monolithic entity called “Psychiatry” has deliberately misled the public as to the causes of mental illness, by failing to debunk the chemical imbalance hypothesis. Indeed, this narrative insists that by promoting this simplistic notion, psychiatry betrayed the public trust and made it seem as if psychiatrists had “magic bullets” for psychiatric disorders. (Lurking in the back-story, of course, is Big Pharma, said to be in cahoots with psychiatry so as to sell more drugs.)

However, if you had actually investigated the APA’s 2005 statement, you would have chosen answer 4. Here is the complete passage from the APA’s “Healthy Minds” Web site, intended for the general public:

The exact causes of mental disorders are unknown, but an explosive growth of research has brought us closer to the answers. We can say that certain inherited dispositions interact with triggering environmental factors. Poverty and stress are well-known to be bad for your health—this is true for mental health and physical health. In fact, the distinction between “mental” illness and “physical” illness can be misleading. Like physical illnesses, mental disorders can have a biological nature. Many physical illnesses can also have a strong emotional component [italics added].2

In fact, in the same year as the APA statement, Drs Thomas Insel and Remi Quirion3 wrote a seminal paper proposing that “mental disorders need to be addressed as disorders of distributed brain systems with symptoms forged by developmental and social experiences.” They went on to consider how “environmental factors during critical intervals of development exert long-term effects on gene expression” and suggest that “studying unconscious processes, motivation, or defenses, while at one time the sole province of psychoanalytic therapies, are now also in the domain of cognitive neuroscience.”

Does this sound like a simplistic chemical imbalance hypothesis? I don’t think so. But then, why do antipsychiatry groups and bloggers fail to note the nuances of what psychiatrists have been saying for at least the past decade? My guess is that doing so would undermine the derogatory narrative they wish to promote. And, of course, nuanced statements do not gin up public opinion or sell books.

OK—but weren’t there many psychiatrists in the 1980s and 1990s who advocated a purely biochemical theory of mental illness, often using the metaphor of the chemical imbalance to explain mental disorders to their patients? It’s difficult to answer this question, except in an anecdotal way, but it’s probably true that some psychiatrists did hold a purely biocentric view. And, alas, some undoubtedly used the expression “chemical imbalance” in their clinical practice, without putting it into a broader context for their patients.

It’s also true, as critics of the chemical imbalance hypothesis point out, that the term “imbalance” is misleading. To validate an imbalance, we must first have a quantitative understanding of the optimal neurochemical balance in the brain—and, given the scores of neurotransmitters now identified, this balance has yet to be ascertained. That said, I am not aware of any concerted effort by academic psychiatrists, psychiatric textbooks, or official psychiatric organizations to promote a simplistic chemical imbalance hypothesis of mental illness. That is what I meant when, in a 2011 Psychiatric Times piece, I referred to the chemical imbalance hypothesis as an urban legend.4

But still—shouldn’t psychiatrists in positions of influence have made greater efforts to knock down the chemical imbalance hypothesis, and to present a more sophisticated understanding of mental illness to the general public? Probably so. But there were sincere attempts to do just that, by a number of prominent psychiatrists—beginning nearly 50 years ago, with the developers of the catecholamine hypothesis. As psychiatrist Joseph Schildkraut and neuroscientist Seymour Kety wrote in 1967:

Whereas specific genetic factors may be of importance in the etiology of some, and possibly all, depressions, it is equally conceivable that early experiences of the infant or child may cause enduring biochemical changes, and that these may predispose some individuals to depressions in adulthood. It is not likely that changes in the metabolism of the biogenic amines alone will account for the complex phenomena of normal or pathological affect.5


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