The reasoning
ADHD = persistent inattention and/or hyperactivity‑impulsivity, onset in childhood (several symptoms before age 12), present in ≥2 settings, causing functional impairment, not better explained by another condition. Diagnosis is a clinical, multi‑source synthesis — never a single rating scale or computer test.
Discriminators
- ADHD inattention vs anxiety/depression: distractibility from poor attentional control vs concentration failure from worry/rumination or anhedonia/psychomotor slowing.
- ADHD vs age‑appropriate behaviour / situational restlessness: pervasiveness and impairment.
- ADHD vs learning disorder: these co‑occur; a child inattentive only during reading may have a specific learning disorder, not ADHD.
- Adult "new" ADHD: requires a childhood‑onset trajectory — a 6‑month history of disorganisation is not ADHD; consider mood/anxiety/substance/sleep causes.
Management logic
Psychoeducation + behavioural/educational supports first; pharmacotherapy when impairment warrants — first‑line methylphenidate (children), with lisdexamfetamine/atomoxetine/guanfacine as alternatives. Baseline cardiovascular screen (history, pulse, BP, height/weight) and growth/CVS monitoring on stimulants.
Pitfalls
- Diagnosing from one setting/one instrument.
- Starting stimulants without cardiovascular screening.
Pearls
- 🎯 Pervasive + impairing + childhood‑onset — all three, or reconsider.
- 🩺 Inattention has many causes; ADHD is one, and it's a longitudinal pattern.
Next → The other cardinal neurodevelopmental diagnosis (Concept 31).