The reasoning
A child is a moving baseline. Every symptom is judged against developmental expectation: normal‑for‑age vs excessive/persistent/developmentally inappropriate/impairing. The assessment is cross‑informant (child, parents, teachers, records) and cross‑setting (home, school, peers) — a pattern confined to one setting rarely denotes disorder.
The formulation, expanded for children
Populate: development, temperament/neurodevelopment, physical health, sleep, family (conflict, parental mental illness, attachment), school (learning, bullying), safeguarding, and — in adolescents — substances and sexual/forensic risk. Avoid two errors: blaming parents reflexively, and ignoring the environment entirely. Formulate multifactorially.
Safeguarding is a standing item 🚩
Every child assessment screens for abuse, neglect, and exploitation; unexplained injuries, developmental regression, or disclosure escalate to child‑protection pathways. Suicidal ideation and self‑harm occur in children and adolescents and must be asked about directly.
Framework note
ICD‑11 situates ADHD, ASD, intellectual and learning disorders within neurodevelopmental disorders — not as miniature adult illnesses. Diagnose against developmental trajectory, not adult cross‑sections.
Pitfalls
- Single‑setting, single‑informant diagnosis.
- Missing safeguarding issues behind a "behavioural" presentation.
Pearls
- 🎯 "Abnormal for this developmental stage?" is the gating question.
- 🩺 Cross‑informant + cross‑setting data is the diagnostic substrate in paediatrics.
Next → The commonest neurodevelopmental diagnosis and its rigorous threshold (Concept 30).