Category: F90 F91 F92 F93 F94 F95 F98
F91 — Conduct disorders: facilitator sheet
Teaching objective
F91 requires a persistent pattern (typically judged over 6 months or more) of behaviour such as excessive fighting or bullying, cruelty to people or animals, severe destructiveness, fire-setting, stealing, repeated lying, truancy, or severe and persistent disobedience — described as a behavioural pattern, never as a judgment on the child's character or worth. The fourth character then records the setting (confined to the family versus extending into peer and community life) and the child's peer relationships (unsocialized versus socialized).
Choose material
Worked example · Case: A year-long pattern, not a phase · Case: One shoplifting incident
Worked example
Show scenario
A 12-year-old was caught shoplifting once with a group of friends. His parents and teachers report no other concerning behaviour before or since — no aggression, no destructiveness, no other rule violations — and he has otherwise age-typical peer relationships and school engagement.
Reveal step 1
Step 1 — Check for a persistent pattern: only one incident is described, with no other dissocial or aggressive behaviour reported before or after.
Reveal step 2
Step 2 — Check severity and context: shoplifting once, in a group, is a common adolescent experience and does not by itself indicate a pervasive pattern.
Reveal step 3
Step 3 — Weigh what this means: F91 requires a persistent, repeated pattern; a single isolated act, however concerning to the family, does not meet this threshold.
Reveal step 4
Conclusion — This does not support F91; an isolated incident without a broader pattern is not sufficient for a conduct disorder classification.
Comparison points
F91 is distinguished from F90 by which feature is primary — rule-violating, aggressive conduct in F91 versus attention/activity regulation difficulty in F90, though the two can co-occur (F90.1). It is distinguished from F92 by the absence (in F91) of a genuine, persistent, co-occurring emotional disturbance meeting its own threshold. A single antisocial or criminal act, however serious, does not by itself meet F91 without a persistent pattern.
Misconception prompt
Treating a single defiant or antisocial episode as sufficient for a conduct disorder: "He hit another student, so that's conduct disorder."
Ask the class why this reasoning fails before revealing the explanation below.
Reveal why it fails
F91 requires a repetitive and persistent pattern of dissocial, aggressive, or defiant conduct, typically judged over six months or more — not a single incident, however serious. Adolescents and children commonly have isolated episodes of poor judgement or rule-breaking as part of typical development; treating any one such episode as diagnostic conflates ordinary, time-limited misbehaviour with a genuinely persistent behavioural pattern, and risks unfairly labelling a young person based on one moment.
Discussion prompts
Prompt 1
Explain why a single antisocial act is not sufficient for F91.
Prompt 2
Explain the difference between unsocialized and socialized conduct disorder.
Summary
A persistent, repeated pattern of dissocial, aggressive, or defiant conduct beyond ordinary childhood mischief — never a single act, and never a judgment on the child's character.