Some Preliminary Ideas for DSM-6
DSM-6: Ideas toward a more valid psychiatric classification system.
Updated January 12, 2026 | Reviewed by Jessica Schrader
When I was in graduate school at the University of Pittsburgh, the chairman of the psychiatry department was serving as chair of the DSM-5 Task Force. It was an exciting place and time to be training in a psy discipline, and there was a general sense that important things were happening in the field. These early experiences cemented in me an interest not only in psychotherapy but also psychiatric classification, as I realized that so much of what we think and do depends on how we define mental disorders.
The DSM-5 was published in 2013 and the DSM-5-TR was released in 2022. The American Psychiatric Association is now in the early stages of planning for the next iteration of DSM, which will likely be called DSM-6.
I would like here to offer some very preliminary ideas to improve the DSM classification system. These suggestions are based both on my clinical experience and interest in psychiatric history, and they aim to address several persistent problems in the field. My hope is that they contribute in some small way to thinking around DSM-6.
Establish a diagnostic hierarchy
DSM-III-TR, published in 1987, eliminated many of the diagnostic hierarchies that prevented giving multiple diagnoses to the same patient. This has led to a false comorbidity problem, where symptoms are mistaken for distinct disorders (Maj, 2005). It is not uncommon, for instance, to see patients currently diagnosed with three or more psychiatric illnesses. This practice drives polypharmacy and inappropriate treatment.
For instance, if a person has borderline personality disorder but also has anxiety symptoms, mood symptoms, and attention problems, they most likely do not also have an anxiety disorder, a mood disorder , and ADHD . In practice, however, these patients are routinely misdiagnosed as having multiple conditions and put on a carousel of psychiatric medications, which are ineffective in treating their disorder.
The lack of a diagnostic hierarchy in DSM reflects broader issues of pragmatism and utilitarianism in psychiatric thinking (e.g., the belief that diagnoses should be made if they are "useful" and not necessarily because they are valid), topics covered extensively by my Tufts colleague Nassir Ghaemi (see Ghaemi, 2013).
Emphasize validity of psychiatric diagnoses
The DSM's emphasis on inter-rater reliability since DSM-III has come at the expense of diagnostic validity, and it has led to a proliferation of false (invalid) diagnoses, which patients and clinicians alike believe are "real." If psychiatry is to advance as a scientific discipline, it must prioritize validity —ensuring that categories reflect real entities that differ from one another (discriminant validity).
This tension between reliability and validity goes back to disagreements between Robert Spitzer, chair of the DSM-III Task Force, and psychiatrists at the Washington University in St. Louis, especially Eli Robins, Samuel Guze, and George Winokur. While it is beyond the scope of this post to discuss the intricacies of this debate, suffice it to say that an emphasis on reliability has led to an explosion of DSM diagnostic categories, many of which do not reflect real conditions.
Similarly, some empirically supported diagnostic categories, such as melancholia, have evaded classification in DSM (see Taylor & Fink, 2008).
Ideally, the DSM would be comprised of scientifically valid diagnoses that also possess a high degree of reliability. Utility without validity is useless (Ghaemi, 2016). Limiting DSM to valid diagnoses would significantly reduce the number of disorders.
Restore the multiaxial system
The multiaxial system, which was eliminated in DSM-5, encouraged clinicians to consider multiple dimensions of a patient's condition: not only their clinical syndrome, but also personality functioning, medical conditions, psychosocial stressors, and overall level of functioning. Its removal has fostered a kind of diagnostic tunnel vision, reinforcing biological or psychosocial reductionism.
Restoring a multiaxial approach—and perhaps even adding an axis for etiological formulation, as Spitzer proposed in 1978 (Decker, 2013)—would support a more comprehensive assessment and encourage clinicians to evaluate personality and interpersonal functioning in every patient.
Retain categories while incorporating dimensions
An extensive literature has developed around dimensional versus categorical approaches to psychiatric diagnosis. This is a complex area of study, and dimensional models offer some important insights about the nature of psychopathology. However, I am skeptical of a return to the hyperdimensionalism of pre-DSM-III psychiatry.
It is true that all differences in nature are basically quantitative ones and that categorical distinctions are based on cutoffs on a dimensional scale. This is simply a biological reality and not at all unique to psychopathology. (Hypertension is a good example of dimensionality in general medicine.)
What matters is that individuals with a given psychiatric disorder differ, on average, from those without it, not just in symptoms but in onset, course of illness, prognosis, and treatment response. In other words, the fact that there is overlap between some diagnostic categories does not invalidate the concept that in general the peaks of each disorder (as in a normal distribution) differ significantly from each other.
I believe DSM-6 should resist the broad application of dimensional models and find ways to reasonably integrate dimensional and categorical approaches.
As work on DSM-6 begins, the field faces an opportunity to move beyond the pragmatic compromises that have shaped the manual since DSM-III. Reinstating a diagnostic hierarchy, restoring the multiaxial system, limiting diagnoses to those with empirical validity, and integrating dimensions without eliminating categories would help reestablish psychiatry as a discipline concerned with truth and not merely utility.
In short, we need to make psychiatric diagnosis truer, fewer, and deeper.
Decker, H. S. (2013). The making of DSM-III: A diagnostic manual's conquest of American psychiatry. Oxford University Press.
Ghaemi, S. N. (2013). Taking disease seriously in DSM. World Psychiatry, 12 (3), 210–212. https://doi.org/10.1002/wps.20082
Ghaemi, S. N. (2016). Utility without validity is useless. World Psychiatry, 15 (1), 35–37. https://doi.org/10.1002/wps.20287
Maj M. (2005). "Psychiatric comorbidity": An artefact of current diagnostic systems?. British Journal of Psychiatry, 186 , 182–184. https://doi.org/10.1192/bjp.186.3.182
Taylor, M. A., & Fink, M. (2008). Restoring melancholia in the classification of mood disorders. Journal of Affective Disorders , 105 (1-3), 1–14. https://doi.org/10.1016/j.jad.2007.05.023
Share this post Facebook Bluesky Linkedin Email
There was a problem adding your email address. Please try again.
By submitting your information you agree to the Psychology Today Terms & Conditions and Privacy Policy
Mark L. Ruffalo, LCSW, is an Assistant Professor of Psychiatry at the University of Central Florida College of Medicine and Adjunct Assistant Professor of Psychiatry at Tufts University School of Medicine.
Get the help you need from a therapist near you–a FREE service from Psychology Today.
This article is part of the Bringwise Psychology Journal — daily insights on human behavior, mental health, and personal growth.