About ICD Diagnostica

ICD Diagnostica is an independent platform supporting differential diagnosis of mental disorders based on the WHO ICD-11 classification. Below we describe the project's purpose, the methodology behind our content and the sources we rely on.

In brief
Purpose Structured, free access to ICD-11 diagnostic criteria.
Methodology Content grounded in WHO ICD-11 and the CDDR; sources cited, gaps not hidden.
Independence An independent platform, not affiliated with the WHO. ICD-11 used under CC BY-ND 3.0 IGO.

Why ICD Diagnostica exists

Access to ICD-11 diagnostic criteria is fragmented and incomplete. The original WHO classification is available mainly in English, part of the literature sits behind paywalls, and popular summaries rarely give the full criteria and differential diagnosis.

ICD Diagnostica was created to close that gap: to gather criteria, symptoms and differential-diagnosis guidance in one place, in a clear and structured form. The tool is intended for clinicians – psychologists, psychiatrists, psychotherapists, and students or trainees in those disciplines – as support for diagnostic work, not a replacement for it.

The platform is informational and educational and supports the intellectual work of a qualified professional. It is not a medical device and is not intended for self-diagnosis by people without clinical training.

How we prepare content

  • Substantive basis. Content is grounded in the WHO ICD-11 classification and in the Clinical Descriptions and Diagnostic Requirements (CDDR) for mental disorders.
  • Structure. Every disorder is described in a consistent layout: symptoms, diagnostic criteria, and differential diagnosis with links to related entities.
  • No fabrication. We do not fill content with guesswork. Where data is missing, the field stays empty or flagged – we do not generate information unsupported by a source.
  • Review before publication. Content is prepared and reviewed by a clinical psychologist (see the "Author" section) for substantive accuracy, clinical implications and communicative clarity.
  • Updates. Materials are revised as the classification changes and feedback arrives. Each disorder page carries a last-modified date.

Sources

The substantive content on the ICD Diagnostica platform draws on the following sources:

  • ICD-11 (WHO). International Classification of Diseases, 11th revision, Chapter 6 (mental, behavioural and neurodevelopmental disorders).
  • CDDR. Clinical Descriptions and Diagnostic Requirements for ICD-11 Mental, Behavioural and Neurodevelopmental Disorders – the source of clinical descriptions and diagnostic requirements.
  • Peer-reviewed literature. Used as a supplement, where it clarifies the clinical context.

Author

Patryk Malejka
MSc in Psychology (clinical specialisation)

A practising psychologist and author of scientific publications in clinical and applied psychology. In day-to-day clinical practice he works integratively, drawing primarily on cognitive-behavioural therapy and schema therapy, with a particular focus on anxiety disorders, occupational stress and attachment mechanisms. Alongside this he conducts research, concentrating on the practical application of psychological knowledge in assessment and intervention, as well as on the methodological aspects of psychological evaluation. In his published work he prioritises methodological rigour, conclusions firmly anchored in empirical data, and clear language accessible to a non-academic reader. As a reviewer he attends both to substantive accuracy and clinical implications of the content and to its communicative clarity.

Author and reviewer of substantive content
ICD-11
Classification source
ICD-11 © World Health Organization (WHO) 2019, icd.who.int/browse11. Used under the Creative Commons Attribution-NoDerivatives 3.0 IGO license (CC BY-ND 3.0 IGO). ICD Diagnostica is an independent platform and is not affiliated with, sponsored by, or endorsed by the WHO.
Go to icd.who.int
ICD Diagnostica · Independent platform · Not affiliated with the World Health Organization · ICD-11 used under CC BY-ND 3.0 IGO
Document: About the project · Version: v1.0 · Last updated: 21 May 2026