Psychiatric classification systems only make sense within particular conceptual frameworks. Moreover, these frameworks make certain assumptions about knowledge-making, the origin of disease, and principles of diagnosis – principles that dictate, for example, whether we classify disease based upon symptoms or causes.
New scholarship by psychiatrists Awais Aftab and Elizabeth Ryznar provides a comprehensive review of the conceptual and historical evolution of psychiatric nosology, which refers to the branch of medical science dealing with the classification of diseases.
While the model of diagnosing psychiatric illness based on collections of symptoms, enshrined in the DSM-V, is a recent invention, the practice of looking to symptoms instead of causes to categorize disease is not new. As Aftab and Ryznar write:
“The tension between symptom-based (i.e., descriptive) versus causation-based (i.e., aetiological) classification systems was … present in the 18th century, and it continues to this day.”
Many, including former NIMH head Thomas Insel, have criticized the DSM’s symptom-based approach to classifying mental challenges. Indeed, the DSM has been assessed as “scientifically meaningless,” enshrining diagnostic categories that are contradictory, subjective, and heterogenous to the point of being unusable. Further, DSM panelist members have documented ties to the pharmaceutical industry, presenting egregious conflicts of interest. Others have pointed out that the DSM’s classification of mental disorders is also based on culturally and historically contingent symptom profiles.
Critics of psychiatric diagnosis in general point to the physical, mental, and epistemic violence that is enabled and legitimated via appeals to psychiatric categories. In addition, institutional acts of categorization can themselves be iatrogenic, racially-biased, enact epistemic violence, and justify harmful practices such as forced treatment that violate international principles of human rights and exacerbates problems of racial justice.
In their previous work, both Aftab and Ryznar have advocated for the reform of psychiatric training and practice through increased engagement with the philosophical assumptions of the field, critiques made by critical psychiatrists and service-users, the history of psychiatry, and approaches that avoid biological reductionism.
In their new article, Aftab and Ryznar place the ascendancy of the DSM, and the ultimate move toward symptom-based diagnostic systems, within the historical context of new demands for statistics emerging in the arena of public health throughout the 19th and 20th centuries.
In the mid-19th century, they write, that “the field of medical statistics experienced burgeoning growth driven by the need for accurate reporting of hospitalizations and causes of death.”
Thus, they argue that the DSM was born under increased pressure to quantify and report on health statistics for use in public planning. Although all classification systems have been subject to criticism for various gaps and issues, the DSM helped further the goals of medical statisticians.
The history of psychiatric nosology thus emerges as complex and divergent, pushed in one direction by biopolitical projects of classification and statistical analysis, and on the other by attempts to locate and treat underlying causes of mental abnormality and suffering.
Yet, despite its practical value, the DSM’s failure to meet the standards of medical science could point to a more enduring revelation about the nature of the subject of psychiatry itself.
“The difficulties and uncertainties that psychiatric nosology faces do not necessarily represent a ‘failure’ of the psychiatric project,” Aftab and Ryznar write, “but could also represent a ‘discovery’ of sorts of the limitations of the project of scientific classification itself.”
“Such a realization could conceivably help improve strained relationships between psychiatry and other stakeholders, facilitate pluralism in practice, and enhance clinical care.”
This nuanced, pluralist approach to the tenets of mainstream psychiatry would be a welcome change for those who have suffered under the DSM’s classificatory regime.
Aftab, A., and Ryznar, E. (2021). Conceptual and historical evolution of psychiatric nosology. International Review of Psychiatry, 33(5), pp. 486-499. (Link)