Tia, a 14-year-old who is accompanied by her mother, requests assessment of suspected ADHD. Both her school and mother report that Tia is oppositional, inattentive, argumentative and difficult to please.

Tia’s academic performance is poor, and she has consistently needed extra help from her teachers. During primary school, it was noted she had poor fine motor skills and some speech and language difficulties, for which she attended speech and occupational therapy.

Her past medical history is unremarkable, she was delivered vaginally at term after an uncomplicated pregnancy, is fully vaccinated and has had no significant childhood event or major illness.

Tia has two half-siblings — a sister, aged 11.5, and a brother, aged seven — who each have different fathers. Both her siblings are well and are doing fine at school.