What is the difference between ICD-11 and DSM-5-TR for ADHD?

What the sources actually say

The main sources here are the International Classification of Diseases 11th Revision, Mortality and Morbidity Statistics, published by the World Health Organization, latest release 2026-01, and the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision, maintained by the American Psychiatric Association, with public update pages including 2025 updates. Together, they show that ADHD exists in both systems, but the systems serve different purposes: ICD-11 is the classification and coding framework, while DSM-5-TR is the diagnostic manual. This is descriptive guidance for clinicians and health systems, not a treatment guideline, and it does not replace an individual assessment.

The sources do not say that one system is more correct than the other, and they do not tell a clinician to diagnose ADHD from a checklist alone. The APA also states that DSM-5-TR is a manual for assessment and diagnosis and does not provide treatment guidelines. If low mood, anxiety, substance use, or thoughts of self-harm are part of the picture, urgent help matters more than labels. In Canada, call or text 9-8-8 for immediate mental health crisis support, or call 911 if there is immediate danger.

They do different jobs

The clearest difference is function. DSM-5-TR defines the disorder in a detailed psychiatric manual. ICD-11 classifies and codes health conditions across the health system. WHO describes ICD-11 MMS as the release used for mortality and morbidity statistics, and the ICD browser shows it by release version. APA describes DSM-5-TR as the official list and text revision used for assessment and diagnosis of mental disorders.

For a person being assessed for ADHD, that means the clinician may document the presentation using DSM-5-TR language during the interview and write an ICD code into the chart, report, claim form, or institutional record. That practical split matters because two notes can describe the same person accurately while looking different on paper.

• DSM-5-TR is centred on psychiatric diagnostic definitions and related text.
• ICD-11 is centred on standardised classification across health settings and countries.
• A clinic, insurer, school support process, or hospital record may ask for a code even when the assessment itself was structured using DSM-5-TR.
• The two systems overlap, but they are not page-for-page copies of each other.

Definitions and codes are not identical

The second difference is how ADHD is organised and labelled. In ICD-11, ADHD appears as 6A05 Attention deficit hyperactivity disorder within the mental, behavioural or neurodevelopmental disorders chapter. WHO’s browser also publishes release-specific coding versions, with 2026-01 listed as the latest ICD-11 MMS release. DSM-5-TR includes ADHD as a recognised mental disorder within its diagnostic classification, but the APA’s public pages focus on the manual, criteria updates and ICD-10-CM coding updates rather than giving open-access full criteria text.

In practice, ICD-11 and DSM-5-TR use similar core ideas, persistent inattention and or hyperactivity-impulsivity causing impairment, but the wording, presentation labels and coding structure are not identical. That matters when a clinician is writing a diagnosis letter, a school note, or a report for another health professional.

What changes in a Canadian assessment

For adults in Canada, or for a parent helping a teen through an assessment, the difference usually shows up in documentation, not in the lived symptoms. A clinician still has to take a proper history, look at current symptoms, ask about functioning across settings, and consider other explanations such as sleep problems, anxiety, depression, trauma, learning issues, substance use, or stress. If symptoms overlap with worry or panic, see What is the difference between ADHD and anxiety?.

If you need help now for thoughts of self-harm, substance use, depression, or anxiety, call or text 9-8-8 in Canada, or call 911 if there is immediate danger.

The practical questions are usually these: what wording is used in the note, what code goes on the form, and what standard does the service say it follows. For example, Finding Focus states that its adult assessment is based on DSM-5-TR criteria and CADDRA-aligned practice. Those are service facts, not evidence that one manual is better.

• If a clinician says the assessment used DSM-5-TR, that tells you the diagnostic framework used in the interview.
• If the paperwork includes an ICD code, that tells you how the condition was classified for records or reporting.
• If you need a more detailed breakdown of one ICD-11 ADHD presentation, see Who ICD-11 6A05.2 combined presentation ADHD?.
• If you are deciding between care formats, see What's the difference between an online and in-person ADHD assessment?.

What to ask for on your paperwork

If you need documentation for work, school, another clinician, or your own records, ask for the diagnosis to be written clearly in words and, if relevant, with the code used by that service. That reduces confusion later. The most helpful documents usually state the diagnostic framework used, the diagnosis wording, the functional impact, and what follow-up is recommended.

• Ask which framework was used, DSM-5-TR, ICD-11, or both.
• Ask whether the document needs a descriptive diagnosis only, or also a code.
• Ask whether the note is meant for a family doctor, school, workplace, insurer, or specialist, because the format may differ.
• Ask whether the clinician considered overlapping conditions, especially if symptoms could also fit anxiety, depression, sleep problems, or stress.