Can ICD-11 replace DSM-5 as the clinician's diagnostic guide? That is what Mats Adler asks in this overview of the updated diagnosis classification from the World Health Organization.
The International Classification of Diseases (ICD) is the World Health Organization's system for the coding of diagnoses. It is now being updated for the first time in 30 years. In 2022 WHO adopted the eleventh edition of the ICD, which is available in English via the Internet (link). ICD-11 is being translated by the Swedish Board of Health and Welfare and the work is expected to be completed by the end of 2024.
In Sweden, the Diagnostic and Statistical Manual of Mental Disorders (DSM) has a strong position as a diagnostic support, partly due to the system's clear criteria sets, which allow a relatively similar assessment of which diagnostic categories a patient should be attributed to. In the ICD-10 (Swedish edition) only a few diagnoses are described in detail, and often we were left with codes without any further definition or description. ICD-11 gives almost all diagnoses updated descriptions. ICD-11 also has a new chapter structure with new codes and new diagnoses and diagnostic principles are being introduced. [1],[2]
For those using "MINI-D-5" as a diagnostic reference, or diagnostic instrument such as the MINI, it is important to know that there is a significant difference in how diagnoses are defined in ICD-11 (and 10) versus the DSM. The DSM system has its historical basis in research needs of clear boundaries for which individuals should be included in research studies (coming from Research Diagnostic Criteria from the 1970s). Hence the approach to describe exact limits for the number of criteria that must be met or the duration by which they must appear. In ICD-11, diagnoses are described in the form of concise texts, called "vignettes", where precise limits rarely are given for the number of symptoms and duration (although it does occur, for example for depression). The ICD system's vignettes are suitable for clinical evaluations as the vignettes can serve as type descriptions for a so-called "prototypical" overall assessment. [3]
ICD-11 introduces a number of novelties in terms of individual diagnoses, some of which I will address. In some chapters, the ICD-11 takes steps towards a so-called ”dimensional” diagnostic approach, which builds on the concept that psychiatric psychopathology increases gradually and that there are no sharp boundaries in the number, intensity or duration of relevant symptoms underlying psychiatric conditions. This most profoundly applies to the Personality syndrome chapter which changes in a way described as a "paradigm shift". [4],[5] ICD-11 removes the traditional categories of personality syndromes and replaces them with a single main diagnosis based on the presence of long-standing problems in the functioning of aspects of the self and/or interpersonal dysfunction The diagnosis is graded in severity and can be provided with specifications that harmonize with the well-known "five-factor model" of personality. [6] Sets of dimensional qualifiers have also been introduced to describe the symptomatic manifestations of schizophrenia and affective disorders.
Another paradigm shift in the ICD-11 is that transgender identity no longer classifies as a mental disorder. It is being renamed “gender incongruence” and moved to a chapter on sexual health.
In the Neurodevelopmental chapter, the separate Attention Deficit Disorder (ADD) diagnosis is abolished and included as a subtype of ADHD with “predominantly inattentive presentation”. Asperger's syndrome is incorporated under the diagnosis "autism spectrum disorder". Both changes in this chapter harmonize with the DSM-5.
ICD-11 clarifies the diagnosis of "adjustment disorder". A new characteristic has been added for the diagnosis based on its typical thought content, called "preoccupation with the stressor", which creates a better demarcation against depression and other diagnoses. [7]
In any event, clinicians should already take a look at the system. Because ICD-11 is coming whether we like it or not.
Importantly, in ICD-11 a definition of "complex post-traumatic stress disorder" is introduced, which may facilitate diagnostics, research and treatment of this serious condition. [8]
In the OCD chapter, new diagnoses will be included, among others “Olfactory reference syndrome”, “Hoarding disorder” and "Excoriation syndrome" (also called skin-picking) and diagnoses such as Body dysmorphic disorder and Trichotillomania are moved to this chapter.
"Prolonged grief disorder" is a new diagnosis to describe abnormally persistent and disabling responses to bereavement. Binge eating without compensatory behaviors was given an "unspecified diagnosis" in ICD-10. In ICD-11, this behavioral disorder has its own diagnosis designation. Avoidant/restrictive food intake disorder, Body integrity dysphoria and Gaming disorder are other news in ICD-11.
Will ICD-11 replace DSM-5 as the clinician's "desk reference" in diagnostics? Most clinical research are based on categories defined in the DSM-system, which implies that the system will continue to play an important role. However, the clinical usefulness of the vignettes, the updating of many diagnoses and the steps in a dimensional direction speak for the ICD-11. In any event, clinicians should already take a look at the system. Because ICD-11 is coming whether we like it or not. □
References by request
Reed GM, First MB, Kogan CS, et al. Innovations and changes in the ICD-11 classification of mental, behavioural and neurodevelopmental disorders. World Psychiatry 2019; 18(1): 3-19.
Gaebel W, Stricker J, Kerst A. Changes from ICD-10 to ICD-11 and future directions in psychiatric classification Dialogues in clinical neuroscience 2020; 22(1): 7-15.
Adler M. Klinisk Psykiatrisk Diagnostik. Stockholm: Psykiatriutveckling Sverige; 2019.
Tyrer P, Mulder R, Kim YR, Crawford MJ. The Development of the ICD-11 Classification of Personality Disorders: An Amalgam of Science, Pragmatism, and Politics. Annu Rev Clin Psychol 2019; 15: 481-502.
Bach B, Somma A, Keeley JW. Editorial: Entering the Brave New World of ICD-11 Personality Disorder Diagnosis. Frontiers in psychiatry 2021; 12: 793133.
Bach B, Christensen S, Kongerslev MT, Sellbom M, Simonsen E. Structure of clinician-reported ICD-11 personality disorder trait qualifiers. Psychol Assess 2019.
O'Donnell ML, Agathos JA, Metcalf O, Gibson K, Lau W. Adjustment Disorder: Current Developments and Future Directions. International journal of environmental research and public health 2019; 16(14).
Jowett S, Karatzias T, Shevlin M, Albert I. Differentiating symptom profiles of ICD-11 PTSD, complex PTSD, and borderline personality disorder: A latent class analysis in a multiply traumatized sample. Personal Disord 2019.