If you do not change direction,
you may end up where you are heading. Lao Tzu
I often wonder how other medical specialties view psychiatry. I experience a politeness when interacting with non-psychiatric physicians, a collegial deference, but they are aware from their prior “psych” rotations that the field of psychiatry does not play by the same medical model rules as other fields of medicine. This may be a reason they chose another specialty. My medical colleagues may have also wondered why psychiatry is the only specialty with its own DSM.
For example, the Diagnostic and Statistical Manual (DSM), in which there are no actual statistics, requires only symptoms for a diagnosis. Other specialties require additional validators of course of illness, genetics, biomarkers or imaging tests to confirm a diagnosis. In a 2013 blog just before the release of the DSM-5, Thomas Insel MD, then director of NIMH, said the DSM is “at best, a dictionary, creating a set of labels and defining each” and that “its weakness is its lack of validity.” He said that NIMH will “reorient” its research away from the manual. (bold added)
He continued, “Unlike our definitions of ischemic heart disease, lymphoma or AIDS, the DSM diagnoses are based on a consensus about clusters of clinical symptoms, not any objective laboratory measure. He went on to write, “In the rest of medicine, this would be equivalent to creating diagnostic systems based on the nature of chest pain, or the quality of fever.”
Insel said that “elsewhere in medicine this type of symptom-based diagnosis has been abandoned over the past half-century as scientists have learned that symptoms alone seldom indicate the best choice of treatment.” (bold added)
This symptom-based approach has been the guiding principle for nearly two generations of psychiatrists since the publication of the transformative 1980 DSM-III. In the subsequent four editions to the present DSM-5, this has remained the case, i.e., no requirement for other diagnostic validators like course of illness genetics/family history, lab biomarkers or imaging. It should be noted that no DSM has ever included a list of literature citations of supporting studies to document the validity of its expanding list of “disorders”. The decisions are made by committees of mostly academics not involved in research.
The words “disease” or “illness” have not appeared the DSM since 1980 because the American Psychiatric Association could not get enough votes from the prominent psychoanalytic (Freudian) hegemony of that era or American Psychological Association to pass the 1980 edition because those groups were afraid, they might be excluded from insurance reimbursement, since they did not practice within a medical model by treating “diseases”. The other reason for the word “disorder” is that it was thought at that time to be atheoretical, i.e., not psychoanalytic or biological so as not to offend these groups but thereby stepping away from a medical model.
Psychiatry also has its own unique definition of co-morbidity which by counting symptoms and reaching a threshold, additional “disorders” can be added as if all diagnoses are on equal footing. This does not comport with the traditional definition of co-morbidity by Feinstein as “any distinct additional entity that has existed or may occur during the clinical course of a patient who has the index disease under study.” In Feinstein’s formulation, the implication was that a completely different and independent disease occurred at the same time as another disease. These two diseases co-occurred, more often than not, randomly due to the vagaries of nature and genetics. (Feinstein AR. THE PRE-THERAPEUTIC CLASSIFICATION OF CO-MORBIDITY IN CHRONIC DISEASE. J Chronic Dis. 1970 Dec;23(7):455-68).
In other words, the DSM system is not real comorbidity, it does not specify independent, unrelated, simultaneously occurring diseases. It also leads to the DSM avoidance of a Diagnostic Hierarchy.
Below is the psychiatric version of the vertical priority diagnostic system used in the rest of medicine, the lower conditions cannot explain the higher conditions, but the higher can better explain the lower:
- Mood illnesses – mixed, manic or unipolar depression, any of which may have psychosis, agitation, distractibility and anxiety occupy the top position because they can explain everything below but the reverse does not. (This would also include the classic mood temperaments of cyclothymia, dysthymia and hyperthymia).
- Psychotic conditions: schizophrenia & schizoaffective
- 3. Anxiety conditions: OCD, PTSD
- Other: personality traits or “disorders”, ADD
PG Surtees, RE Kendell. Br J Psych, 1979, 135:438-44
The DSM system is horizontal, i.e., one “disorder” is equal to another: MDD, GAD, PTSD, OCD ADHD etc. Each disorder then is treated simultaneously with a mélange of prescription medications often with at cross purposes.
The seminal paper in 1970 by Robins and Guze elaborates the following Diagnostic Validators for psychiatry:
- Symptoms (only requirement for diagnosis in the DSM)
- Course of illness (not required for diagnosis in the DSM)
- Family History/Genetics (not required for diagnosis in the DSM))
- Treatment effects (least helpful i.e., a so called “response” to Adderall is not proof of ADD since every human being can respond with a temporary increase in alertness. However, if a person with severe clinical depression or mania responds to lithium, it would be considered a legitimate treatment effect).
- Lab tests, imaging and/or other bio-markers. (Sadly, none in psychiatry)
(See Robins E., Guze S.B. Establishment of diagnostic validity in psychiatric illness. Its application to schizophrenia. American Journal of Psychiatry, 126, (7) 1970
I am unaware of any medical specialty that had not come up with at least one new blood test over the past 40 years. It is customary for older blood tests or imaging technology to be replaced with newer ones based on advances in research. The American Psychiatric Association continues to say there is not enough good evidence. (Will that day ever come?)
It is customary for older blood tests or imaging technology to be replaced with newer ones based on advances in research. The American Psychiatric Association continues to say there is not enough good evidence. (Will that day ever come?) Click To Tweet
Contrary to some writers in the popular media who criticize what they perceive to be the psychiatric medical model, the DSM was not designed in 1980 to comport with the established medical model in other specialties of medicine. This is what I call a “psychoanalytic hangover”. From the mid to late 20th century virtually every chairman of a department of psychiatry in U.S. medical schools was either a trained psychoanalyst or otherwise steeped in that tradition and residents were taught accordingly. Also, research in psychiatry for drug development and biomarkers has been stymied, for example by the inappropriate compilation of several types of depressions, (called Major Depression in the DSM), of mild non-episodic depression which is not a disease with more severe episodic depression (with or without mania) which is a disease, described since antiquity and formalized by Kraepelin’s true disease concept of Manic-Depressive illness a century ago. Since DSM defined “MDD” is invalid as a disease, research into biomarkers fails.
The separation in 1980 of Manic-Depressive illness into what is now called “bipolar disorder” was based on six years of family studies in the early 1960’s which appeared to suggest that there was a genetic difference between severe clinical depression and those with manic episodes. However, one of the original researchers, Jules Angst, a prominent Swiss psychiatrist, continued his family studies for the next 40 years called the Zurich Cohort, outliving all his subjects (in what Nassir Ghaemi calls psychiatry’s Framingham equivalent) found that there was really no genetic separation between those with severe depression and those with manic and depressive episodes. But when he was invited to present his landmark study to the DSM-5 Mood Disorders committee, they essentially said “this is interesting and thank you for your work but we are not going to reconnect Manic-Depressive Illness since it would be too disruptive to do so now after all these years”.
Kraepelin’s true disease entity of Manic-Depressive Illness, comprising recurrent severe depressions with or without mania, being swept away by a committee decision in spite of the best longitudinal research available, is a blatant example of the unwillingness of the psychiatric establishment to follow where medical research leads as do other medical specialties.
As Nietzsche said over a century ago, “All things are subject to interpretation. Whichever interpretation prevails at one time is a function of power and not truth”.
Psychiatry can do better.
Some of my Disruptive Sources:
- Published works of Hagop Akiskal, Jules Angst, Athanasios Koukopoulos and Nassir Ghaemi.
- Manic-Depressive Illness, Bipolar Disorder and Recurrent Depression 2007 Volumes I & II, Oxford Press. F. Goodwin and K. Redfield Jamison
- Clinical Psychopharmacology – Principals and Practice, Oxford Press 2019 S.N. Ghaemi.
Thank you for the thought provoking post. I believe the most important advances in healthcare in this century will come from the mental health arena. It’s an underappreciated and vastly misunderstood aspect of our overall health.