History of the DSM

Primer

The DSM (Diagnostic and Statistical Manual of Mental Disorders) has a long and storied history in the history of psychiatry. As the cornerstone of psychiatry and guide for millions of clinicians and healthcare providers, it has been the most significant advance in the diagnosis and treatment of mental disorders. However, in the midst of its success, important criticisms of its role have also arisen.

“[The] DSM[-IV] does none of its jobs perfectly and its awkward fit certainly creates a variety of problems. Some clinicians refuse to learn DSM and stick to their own personal prototypes of disorders. Many epidemiological researchers ignore the requirement for clinical significance before making a psychiatric diagnosis and therefore report ridiculously high rates of mental illness in the general population. Some students take the DSM descriptions too literally and lose the patient as they evaluate the criteria. Lawyers often find loopholes because the language of DSM is frustratingly below legal requirements for precision. And so on. But the unifying and synthesizing whole of DSM-IV is still worth much more than would be the accumulated sum of its individual parts. However imperfect, the DSM's special value is as a common denominator that avoids a Babel and is good enough (if admittedly not best) at each of its jobs.”

– Allen Frances, MD, Chair of the DSM-IV Task Force

The Cycle of Classification: DSM I through DSM-5

Blashfield, R. K., Keeley, J. W., Flanagan, E. H., & Miles, S. R. (2014). The cycle of classification: DSM-I through DSM-5. Annual review of clinical psychology, 10, 25-51.

Pre-DSM Era

DSM-I

DSM-II

Even though the DSM II was published in 1968 (!) the following excerpt is sage advice even (and especially) today.

A Tip From the DSM-II...

The diagnostician, however, should not lose sight of the rule of parsimony and diagnose more conditions than are necessary to account for the clinical picture. The opportunity to make multiple diagnoses does not lessen the physician's responsibility to make a careful differential diagnosis.

DSM-III

DSM-IV

DSM-5

Interrater Reliability

The DSM-5 field trials showed the inherent limitations of the DSM's etiologically agnostic approach to diagnosing mental disorders. Some disorders had good interrater reliability (e.g. - major neurocognitive disorder and posttraumatic stress disorder), while others were very poor. The most prominent example is for major depressive disorder, which has a very poor kappa = 0.28 (questionable agreement). One common reason is because the criteria covers a wide range of illness severity, and is a heterogenous condition.[1]

What is the Kappa Statistic?

Many medical diagnostics (e.g. - physical exams, imaging, and other diagnostic tests) often depend on some subjective interpretation by the observers. This is especially true in psychiatry where there are no objective diagnostics, and the clinician is the the diagnostic tool. Thus, the kappa statistic (or kappa coefficient) is the most commonly used statistic to measure the agreement between two or more observers. A kappa of 1 indicates perfect agreement between observers, whereas a kappa of 0 indicates agreement equivalent to chance. As an example, if an illness appears in 10% of a clinic's patients and two clinicians agree on its diagnosis 85% of the time, the kappa statistic is 0.46 (this is similar to the weighted composite statistic for schizophrenia in this DSM-5 Field Trial).[2][3]

Interrater Reliability of Diagnoses From the Initial DSM-5 Field Trials (Adult Diagnoses) Fig. 1

Interrater Reliability of Diagnoses From the Initial DSM-5 Field Trials (Child Diagnoses) Fig. 2

Quotes

The DSM-5 on Boundaries Between Disorders

Although some mental disorders may have well-defined boundaries around symptom clusters, scientific evidence now places many, if not most, disorders on a spectrum with closely related disorders that have shared symptoms, shared genetic and environmental risk factors, and possibly shared neural substrates (perhaps most strongly established for a subset of anxiety disorders by neuroimaging and animal models). In short, we have come to recognize that the boundaries between disorders are more porous than originally perceived.

– (DSM-5, Introduction, page 5)

The DSM-5 on Checklist Diagnoses

The case formulation for any given patient must involve a careful clinical history and concise summary of the social, psychological, and biological factors that may have contributed to developing a given mental disorder. Hence, it is not sufficient to simply check off the symptoms in the diagnostic criteria to make a mental disorder diagnosis.

– (DSM-5, Use of the Manual, page 19)
“A single diagnostic interview, regardless of how reliable, does not capture the essence of what is happening….Accurate diagnosis must be part of the ongoing clinical dialogue with the patient.”

– Freedman, R., Lewis, D. A., Michels, R., Pine, D. S., Schultz, S. K., Tamminga, C. A., ... & Shrout, P. E. (2013). The initial field trials of DSM-5: new blooms and old thorns.

Readings

ICD-10 and ICD-11

In non-North American circles (i.e. - outside of Canada and the United States), countries use the World Health Organization's International Statistical Classification of Diseases and Related Health Problems, also known as the ICD-10.

The diagnostic criteria for the ICD-10 varies from the DSM-5 for a variety of mental disorders. See Tyrer, P. (2014). A comparison of DSM and ICD classifications of mental disorder. Advances in psychiatric treatment, 20(4), 280-285.

Future

Future of Psychiatry

Beyond the Kraepelinian dichotomy

Research Domain Criteria (RDoC)

RDoC is a research framework proposed by the National Institute for Mental Health (NIMH) for new ways of studying mental disorders. It integrates many levels of information (from genomics to self-report) to better understand basic dimensions of functioning underlying the full range of human behaviour from normal to abnormal.

‘Mental illness’ is terribly misleading because the ‘mental disorders’ we diagnose are no more than descriptions of what clinicians observe people do or say, not at all well established diseases.

— Allen Frances, DSM-IV Task Force Chairman, 2015

While DSM has been described as a “Bible” for the field, it is, at best, a dictionary, creating a set of labels and defining each. The strength of each of the editions of DSM has been “reliability” – each edition has ensured that clinicians use the same terms in the same ways. The weakness is its lack of validity. 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. 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. Indeed, symptom-based diagnosis, once common in other areas of medicine, has been largely replaced in the past half century as we have understood that symptoms alone rarely indicate the best choice of treatment.

— Thomas Insel, National Institute of Mental Health Director, 2013

Resources

Articles
Research

References

1) Freedman, R., Lewis, D. A., Michels, R., Pine, D. S., Schultz, S. K., Tamminga, C. A., ... & Shrout, P. E. (2013). The initial field trials of DSM-5: new blooms and old thorns.
2) Freedman, R., Lewis, D. A., Michels, R., Pine, D. S., Schultz, S. K., Tamminga, C. A., ... & Shrout, P. E. (2013). The initial field trials of DSM-5: new blooms and old thorns.
3) McHugh, M. L. (2012). Interrater reliability: the kappa statistic. Biochemia medica: Biochemia medica, 22(3), 276-282.