Getting to the root of mental illness

The Atlantic has a review of a book Mind Fixers: Psychiatry's Troubled Search for the Biology of Mental Illnes, (by Anne Harrington) and it's well worth reading. Let's take some extracts:

It follows that psychiatrists also cannot precisely predict for whom and under what conditions their treatments will work. That is why antipsychotic drugs are routinely prescribed to depressed people, for example, and antidepressants to people with anxiety disorders. Psychiatry remains an empirical discipline, its practitioners as dependent on their (and their colleagues’) experience to figure out what will be effective as Pliny Earle and his colleagues were. Little wonder that the history of such a field—reliant on the authority of scientific medicine even in the absence of scientific findings—is a record not only of promise and setback, but of hubris....

As Harrington ably documents, a series of fiascoes highlighted the profession’s continued inability to answer Clark Bell’s question. Among them was the 1973 vote by the American Psychiatric Association declaring that homosexuality was no longer a mental illness. The obvious question—how scientific is a discipline that settles so momentous a problem at the ballot box?—was raised by the usual critics. This time, insurers and government bureaucrats joined in, wondering, often out loud, whether psychiatry warranted their confidence, and the money that went along with it.

The association’s response was to purge its Diagnostic and Statistical Manual of Mental Disorders (DSM) of the Freudian theory that had led it to include homosexuality in the first place. When the third edition of the DSM came out, in 1980, its authors claimed that they had come up with an accurate list of mental illnesses: Shedding the preconceptions that had dominated previous taxonomies, they relied instead on atheoretical descriptions of symptoms. But as Harrington points out, they did have a theory—that mental illness was no more or less than a pathology of the brain. In claiming not to, she argues,

they were being disingenuous. They believed that biological … markers and causes would eventually be discovered for all the true mental disorders. They intended the new descriptive categories to be a prelude to the research that would discover them.

The DSM-3’s gesture at science proved sufficient to restore the reputation of the profession, but those discoveries never followed. Indeed, even as the DSM (now in its fifth edition) remains the backbone of clinical psychiatry—and becomes the everyday glossary of our psychic suffering—knowledge about the biology of the disorders it lists has proved so elusive that the head of the National Institute of Mental Health, in 2013, announced that it would be “re-orienting its research away from DSM categories.”

I wonder if this review (and the book), is exaggerating a bit?   This part, for example:

The need to dispel widespread public doubt haunts another debacle that Harrington chronicles: the rise of the “chemical imbalance” theory of mental illness, especially depression. The idea was first advanced in the early 1950s, after scientists demonstrated the principles of chemical neurotransmission; it was supported by the discovery that consciousness-altering drugs such as LSD targeted serotonin and other neurotransmitters. The idea exploded into public view in the 1990s with the advent of direct-to-consumer advertising of prescription drugs, antidepressants in particular. Harrington documents ad campaigns for Prozac and Zoloft that assured wary customers the new medications were not simply treating patients’ symptoms by altering their consciousness, as recreational drugs might. Instead, the medications were billed as repairing an underlying biological problem.

The strategy worked brilliantly in the marketplace. But there was a catch. “Ironically, just as the public was embracing the ‘serotonin imbalance’ theory of depression,” Harrington writes, “researchers were forming a new consensus” about the idea behind that theory: It was “deeply flawed and probably outright wrong.” Stymied, drug companies have for now abandoned attempts to find new treatments for mental illness, continuing to peddle the old ones with the same claims. And the news has yet to reach, or at any rate affect, consumers. At last count, more than 12 percent of Americans ages 12 and older were taking antidepressants. The chemical-imbalance theory, like the revamped DSM, may fail as science, but as rhetoric it has turned out to be a wild success.

I would have thought that the "chemical imbalance" theory still has significant, experimental support, even if flawed;  but I am not expert, just someone who finds the topic interesting.