If most of the difficulty is happening at home, most of the work needs to happen with the household in the room. Otherwise the hour of good conversation gets quietly undone by Tuesday.

What the research says

The foundational review of psychosocial treatments for ADHD established behavioural parent training and classroom management as the best supported approaches, and both of them work through the adults around the young person rather than with the young person alone. That literature concerns children rather than families in crisis with an older teenager. The principle it supports is the one above: the setting is part of the treatment, not the backdrop to it.

Strength of evidence: one line of research. A single study, or a theoretical account.