New manual released to support diagnosis of mental, behavioural and neurodevelopmental disorders added in ICD-11

World Health Organization (WHO) has today published a new, comprehensive diagnostic manual for mental, behavioural, and neurodevelopmental disorders: “ The clinical descriptions and diagnostic requirements for ICD-11 mental, behavioural and neurodevelopmental disorders (ICD-11 CDDR)”.

The manual has been developed using the latest available scientific evidence and best clinical practices and is designed to support qualified mental health and other health professionals to identify and diagnose mental, behavioural and neurodevelopmental disorders in clinical settings.

“An accurate diagnosis is often the first critical step towards receiving appropriate care and treatment. By supporting clinicians to identify and diagnose mental, behavioural and neurodevelopmental disorders, this new ICD-11 diagnostic manual will ensure more people are able to access the quality care and treatment they need” said Dévora Kestel, Director, Mental Health and Substance Use Department, World Health Organization.

The new diagnostic guidance, reflecting the updates to the ICD-11, includes the following features:

• Guidance on diagnosis for several new categories added in ICD-11, including complex post-traumatic stress disorder, gaming disorder and prolonged grief disorder. This enables improved support to health professionals to better recognize distinct clinical features of these disorders, which may previously have been undiagnosed and untreated.
• The adoption of a lifespan approach to mental, behavioural and neurological disorders, including attention to how disorders appear in childhood, adolescence, and older adults.
• The provision of culture-related guidance for each disorder, including how disorder presentations may differ systematically by cultural background.
• The incorporation of dimensional approaches, for example in personality disorders, recognizing that many symptoms and disorders exist on a continuum with typical functioning.

The ICD-11 CDDR are aimed at mental health professionals and qualified non-specialist health professionals such as primary care physicians responsible for assigning these diagnoses in clinical settings as well as other health professionals in clinical and non-clinical roles, such as nurses, occupational therapists and social workers, who need to understand the nature and symptoms of mental, behavioural and neurodevelopmental disorders even if they do not personally assign diagnoses.

The ICD-11 CDDR were developed and field-tested through a rigorous, multi-disciplinary and participatory approach involving hundreds of experts and thousands of clinicians from around the world.

Notes:

• The CDDR are a clinical version of ICD-11 and thus complementary to the statistical reporting of health information, referred to as the linearization for mortality and morbidity statistics (MMS).
• The World Health Organization (WHO) Eleventh Revision of the International Classification of Diseases (ICD-11) is a global standard for recording and reporting diseases and health related conditions. It provides standardized nomenclature and common health language for health practitioners across the world. 
• ICD-11 was adopted at the World Health Assembly in May 2019 and came into effect formally in January 2022.