F91Conduct disorders
Code usage status
Primary diagnosis
Select a more specific code
Apply only when it matches the confirmed diagnosis and the documented clinical record.
Specificity
Do not use F91 directly
Use the most specific code supported by the record.
- Chapter V
- Mental and behavioural disorders
- Group F90-F98
- Behavioural and emotional disorders with onset usually occurring in childhood and adolescence
- Official Vietnamese name
- Rối loạn ứng xử
- Additional WHO coding guidance
- Disorders characterized by a repetitive and persistent pattern of dissocial, aggressive, or defiant conduct. Such behaviour should amount to major violations of age- appropriate social expectations; it should therefore be more severe than ordinary childish mischief or adolescent rebelliousness and should imply an enduring pattern of behaviour (six months or longer). Features of conduct disorder can also be symptomatic of other psychiatric conditions, in which case the underlying diagnosis should be preferred. Examples of the behaviours on which the diagnosis is based include excessive levels of fighting or bullying, cruelty to other people or animals, severe
Related F91 codes
F91.0
Primary diagnosis candidate
Conduct disorder confined to the family context
F91.1
Primary diagnosis candidate
Unsocialized conduct disorder
F91.2
Primary diagnosis candidate
Socialized conduct disorder
F91.3
Primary diagnosis candidate
Oppositional defiant disorder
F91.8
Primary diagnosis candidate
Other conduct disorders
F91.9
Primary diagnosis candidate
Conduct disorder, unspecified
Clinical record checklist
View coding guide →- Confirm that the code matches the final documented diagnosis.
- Use one primary-diagnosis code and record only relevant additional conditions.
- Review Ministry indicators, inclusions, exclusions and notes.
- Do not infer a diagnosis beyond the clinical record.
2026 regulatory basis
Indicators are taken from columns 24–29 of the classification accompanying Circular 06/2026/TT-BYT, cross-referenced with Decision 1849/QĐ-BYT and Official Dispatch 4059/BYT-BH.
