[ICD-11: Neurocognitive Disorders]

Area of Science:

• Neurology
• Psychiatry
• Medical Classification Systems

Background:

• The International Statistical Classification of Diseases and Related Health Problems (ICD-11) Beta Draft introduces significant changes to the classification of mental, behavioral, or neurodevelopmental disorders (Section 06), replacing the ICD-10 F0-section.
• Progress includes dropping the
• organic
• syndromes concept and focusing on acquired conditions with cognitive symptoms.
• The classification of neurodegenerative disorders, particularly Alzheimer's disease (AD), has been revised.

Purpose of the Study:

• To analyze the changes in the ICD-11 Beta Draft concerning the classification of mental, behavioral, or neurodevelopmental disorders, with a focus on dementia and Alzheimer's disease.
• To evaluate the implications of the syndromal approach in ICD-11 for diagnosis and treatment, especially in resource-limited settings.
• To highlight the limitations of ICD-11 in incorporating biomarkers for neurodegenerative diseases like Alzheimer's disease.

Main Methods:

• Comparative analysis of ICD-11 Beta Draft (Section 06 and Section 08) with ICD-10.
• Review of diagnostic criteria for dementia and minor neurocognitive disorder within ICD-11.
• Assessment of the impact of biomarker exclusion on the classification of Alzheimer's disease.

Main Results:

• ICD-11 Section 06 adopts a syndromal approach for dementia, such as dementia due to Alzheimer's disease (AD), but does not yet incorporate biomarkers or the molecular concept of AD.
• Alzheimer's disease can be classified in Section 08 without reference to symptoms, but also lacks biomarker integration, creating diagnostic uncertainty.
• Minor neurocognitive disorder classification in Section 06 has been modified to allow association with a disease (e.g., AD) but still without mandatory biomarker reference.

Conclusions:

• The syndromal approach in ICD-11 Section 06 is practical for global access to diagnosis and treatment, as biomarkers are not universally available and current therapies target dementia rather than molecular pathology.
• The absence of biomarker integration in ICD-11 is a significant limitation for the development and application of targeted treatments for Alzheimer's disease, such as anti-amyloid therapies.
• Further revisions of ICD-11 are needed to incorporate advancements in biomarker research and molecular understanding of neurodegenerative diseases to improve diagnostic accuracy and therapeutic development.