Why DSM-III, IV, and 5 are Unscientific
Why DSM-III, IV, and 5 are Unscientific
A Spirited Exchange about the Biology of Mental Disorders and DSM-5
James L. Knoll, IV, MD
The spirited exchange between Drs Ronald Pies and Nassir Ghaemi is, I contend, good for the field. Rather than avoid the sensitive or uncertain issues, both psychiatrists turn to face them with their own thought provoking styles and piercing insight. Would that we had more such collegial exchanges in psychiatry. Drs Pies and Ghaemi model for us how to abandon our defensiveness in an objective, respectful and passionate discourse.
As nobel laureate Erick Kandel points out, our field is highly complex, quite young and "our understanding of the biology of mental disorders has been slow in coming." But it is, in fact, slowly progressing. The question of how long it will take to gain a more precise understanding of the underpinnings of mental illness has no definite answer. Or as Dr Theodore Pearlman has stated - "is any psychiatrist's guess."
And so in this spirit of continued scholarly dialogue, I offer a well-reasoned, trenchant response to Dr Ghaemi by Dr Pearlman, which can be found at the end of Dr Ghaemi’s esssay.
Dr Ron Pies makes many insightful comments in the accompanying analysis. My view about why DSM revisions have been unscientific is based on concepts of science that are in agreement with much of what he describes. If science is defined as some kind of systematic study of observed experience applied to hypotheses or theories, and then confirmation or refutation of those hypotheses or theories, followed by new hypotheses or theories that are further tested and refined by new observations – if this is the core of any scientific inquiry, I think that no objective observer can attribute the history of DSM-III, IV, and 5 to anything that approximates this process.
Let’s review this history, so well documented now by historian Hannah Decker with archival, often unpublished evidence for DSM-III.1 In the 1970s, scientific studies that meet the above definitions were collected mainly by researchers centered at the Washington University of St. Louis, and about 2 dozen diagnoses were found to be definable based on such empirical evidence. These were published a few times, lastly in 1978, as the Research Diagnostic Criteria. Within 2 years, Robert Spitzer had taken those scientifically-based diagnoses as the basis for DSM-III, but, through an immense amount of political wheeling-and-dealing (documented in painful detail by Decker), he produces 292 diagnoses. Obviously, in 2 years, a huge amount of scientific research did not suddenly identify 270 new diagnoses. Fourteen years later, with DSM-IV, 365 diagnoses were produced, but the original 270 were little changed. Now, about 20 years later, we still have almost 400 diagnoses, with little change in the original 292 from the Groundhog Year of 1980.
How were these other 200 to 300 diagnoses developed? Was it through a scientific process? As so well documented by Decker and historian Edward Shorter2 and others who observed the process, like Michael Alan Taylor,3 these other diagnoses were based almost entirely on the opinions and beliefs of leaders and interest groups in the psychiatric profession. Why do we have about 10 personality “disorders”? Because psychoanalysts believe in those ideas. Were those ideas tested with observational studies, and then revised based on confirmations and refutations of their content? Not before 1980, and hardly since. As an example, Taylor describes a DSM-IV conference on personality where a huge amount of scientific research was presented on personality traits, and then the DSM-IV leaders stated clearly that they would ignore that scientific evidence and would hardly change the DSM-III personality disorder definitions at all.3 Twenty years later, after literally thousands more studies with some of the best possible scientific evidence possible in experimental psychology, the DSM-5 task force had no choice but to admit the need to add personality dimensions to the nosology. It got all the way to the APA Board of Trustees, and within weeks of publication, was simply rejected tout court.
The original DSM-III personality disorders were almost completely based on psychoanalytic opinion, with hardly any scientific validity literature to support them, as documented well by Hannah in her archival research. In the intervening 30 years, a number of scientific validity studies (using the classic nosology validators of phenomnelogy, course, genetics, and biological markers) have invalidated most DSM-IV personality disorders; in other words, they have been falsified scientifically. In fact, this was the scientific conclusion of the personality disorder research summary provided for DSM-5 by the world’s most prominent personality researchers.4 And yet DSM personality disorders have remained little changed in DSM-5 by fiat. This is another proof of being unscientific: the DSM nosology refuses to accept the falsification of its cherished beliefs.
This is the problem. It’s not complicated, and philosophically difficult. If you have opinion, and nothing else, it’s not science. If you refuse to change your opinions, it’s not science. Most of DSM has been based on opinion, and our profession has refused to change most of that opinion for 2 generations. How can anyone imagine that any profession would ever experience progress, much less scientific progress, if it refuses to change its opinions, themselves based on nothing but prior opinion?
We are much more ignorant than Hippocrates over 2 millennia ago. He knew that opinion breeds ignorance, while science is the father of knowledge. We mistake our opinions for science.