ICD‐11 sessions at the 19th World Congress of Psychiatry

At the 19th World Congress of Psychia­try, held in Lisbon, Portugal, from 21 to 24 August 2019, a plenary session, an educational course and several individual pres­entations were devoted to the Clinical De­scriptions and Diagnostic Guidelines developed by the World Health Organization (WHO) Department of Mental Health and Substance Abuse for the chapter on Mental, Behavioural and Neurodevelopmental Disorders of the 11th revision of the International Classification of Diseases and Related Health Problems (ICD‐11).

The ICD‐11 has been adopted unanimously by the 72nd World Health Assembly in Geneva on May 25, 2019, although reporting of health statistics based on the new classification will only begin on January 1, 2022. Up to that date, the WHO Member States will keep on using the ICD‐10 for reporting data ¹ .

The ICD‐11 classification of mental disorders includes the following groupings: neurodevelopmental disorders, schizophrenia and other primary psychotic disorders, mood disorders, anxiety and fear‐related disorders, obsessive‐compulsive and related disorders, disorders specifically associated with stress, dissociative disorders, feeding and eating disorders, elimination disorders, disorders of bodily distress and bodily experience, impulse control disorders, disruptive behaviour and dissocial disorders, personality disorders, paraphilic disorders, factitious disorders, neurocognitive disorders, and mental and behavioural disorders syndromes due to disorders or diseases not classified under mental and behavioural disorders ² .

The Clinical Descriptions and Diagnostic Guidelines for the ICD‐11 classification of mental disorders have been tested through Internet‐based field studies and clinic‐based field studies.

The Internet‐based field studies, implemented through the Global Clinical Practice Network, including about 15,000 clinicians from 155 countries, reported that the diagnostic agreement for several groups of disorders (e.g., disorders specifically associated with stress, and feeding and eating disorders) was considerably higher for the ICD‐11 compared with the corresponding ICD‐10 categories ³ .

The clinic‐based field studies, conduct­ed in clinical settings, found that the interrater reliability for the main groups of mental disorders ranged from moderate to almost perfect (.45 to .88) and was generally superior to that obtained for ICD‐10 ⁴ . Concerning clinical utility, the diagnostic guidelines were perceived as easy to use, corresponding accurately to patients’ presentations, clear and understandable, providing an appropriate level of detail, taking about the same or less time than clinicians’ usual practice, and providing useful guidance about distinguishing disorder from normality and from other disorders5, 6, 7.

At the World Congress, the plenary session mostly dealt with the implementation of the new classification system, that will involve the interaction of the classification with each country's laws, policies, health systems and information infrastructure. G. Reed, the coordinator of the process of development of the new system, and K.M. Pike, from Columbia University, New York, illustrated the multiple modalities developed for training a vast array of international health professionals. D. Kestel, Director of the WHO Department of Mental Health and Substance Use, described how the new classification fits the most important plans and priorities for the Department going forward. M.E. Medina‐Mora, O. Gureje, J. Huang, D.J. Stein, M. Pinto da Costa and N. Sartorius discussed various aspects of the implementation progress and provided recommendations for what the WHO should do in order to ensure that the ICD‐11 achieves its potential around the world. M. Maj, who chaired the session with G. Reed, summarized some lessons that should be learnt from the process of implementation of previously developed classification systems.

The educational course of the Con­gress provided training on the use of the Clinical Descriptions and Diagnostic Guide­lines for schizophrenia and other primary psychotic disorders, mood disorders, and obsessive‐compulsive and related disorders. The course was based on the use of clinical vignettes describing real cases, followed by a discussion of diagnos­tic dilemmas, including some crucial differences between the ICD‐11 and DSM‐58, 9, as well as the dimensional approach recently advocated by several experts10, 11, 12 and partially implemented in the ICD‐11.

Overall, the sessions emphasized the strong collaboration between the WHO and the WPA in all the steps of the development and testing of the ICD‐11 chapter on Mental, Behavioural and Neurodevelopmental Disorders, and the long‐term partnership that will now be established between the two organizations in the dissemination and implementation of the diagnostic system.