Categories Related to Gender Identity in ICD-11 and DSM-5 Sensitivity, Specificity and Ability to Predict Gender-Affirming Medical Procedures

Background: The most recent versions of the two main classification systems for mental disorders—the Eleventh Revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-11) and the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM–5) —differ substantially in terms of diagnostic categories related to gender incongruence (GI). In contrast to DSM-5, in ICD-11 these conditions are explicitly not considered mental disorders and neither distress nor dysfunction is a required feature.Methods: A global field study of transgender adults in six countries was conducted to compare ICD-11 and DSM-5 diagnostic formulations in terms of their sensitivity, specificity, and ability to predict gender-affirming medical procedures (GAMP).Outcomes: A total of 629 participants completed a structured interview exploring features of GI, distress, dysfunction, and history of GAMP. Using ROC analysis, the sensitivity of the diagnostic requirements was equivalent for both systems, but ICD-11 showed greater specificity than DSM-5. IRT analyses showed that the ICD-11 diagnostic formulation was more parsimonious and contained more information about the caseness of the individual than the more constrained DSM-5 model.Interpretation: The ICD-11 diagnostic requirements for GI appear to be valid and scientifically well-founded. Additional diagnostic requirements in DSM-5 do not help to identify transgender individuals seeking GAMP.Funding Statement: This study was partially funded by unrestricted grants by the World Health Organization Department of Mental Health and Substance Abuse to participating institutions in Brazil, India, Lebanon, Mexico, and South Africa for the development and implementation of ICD-11 field studies. Financial support for the French study was delivered by the Direction Générale de la Santé (DGS).Declaration of Interests: Authors declare no conflict of interests. At the time of the study R. Robles, J.W. Kelley, P. Sharan, D. Stein, B. Khoury, M.E. and Medina-Mora were Consultants to the ICD-11 Field Studies Coordination Group, reporting to the International Advisory Group the WHO International Advisory Group for the Revision of ICD-10 Mental and Behavioural Disorders; and G.M. Reed was a member of the WHO Secretariat, Department of Mental Health and Substance Abuse, WHO. The WHO Department of Mental Health and Substance Abuse provided consultation regarding the focus and methodology of the study, none of these entities dictated the final form of the study. Unless specifically stated, the views expressed in this article are those of the authors and do not represent the official policies or positions of WHO or of the ICD-11 Field Studies Coordination Group.Ethics Approval Statement: The study was approved by the IRBs of all participating institutions. All participants provided written informed consent.