Substance intoxication, withdrawal and use disorders in youth — branching viva

Opening

Examiner: A 16-year-old is in your clinic with daily cannabis use since age 13, falling school marks, a new and risky peer group, and a CRAFFT screen positive on five items. His parents have read that cannabis causes psychosis and are frightened. How do you frame this assessment? ^[3]

Candidate: I would treat this as a likely cannabis use disorder within an SBIRT framework. I would take a structured, confidential, multi-informant history — the young person alone for the substance, risk and mental-health history — screen and confirm the diagnosis on DSM-5 criteria, assess mental state and suicide risk, and only then move to a stepped-care plan. I separate three things at every encounter: intoxication, withdrawal and the use disorder. ^[3]

Branch 1 — diagnosis

Examiner: What DSM-5 criteria make this a use disorder rather than experimentation? ^[1]

Candidate: A substance use disorder is two or more of eleven criteria in twelve months, drawn from four clusters. He has impaired control (failed efforts to cut down), social impairment (school decline, withdrawal from sport, risky peer group), risky use (driving after using), and pharmacological change (tolerance and a withdrawal syndrome). He meets multiple criteria, so this is at least a moderate disorder — experimentation would not meet the criteria at all. ^[1]

Examiner (probe): Why not just rely on a urine drug screen? ^[3]

Candidate: A urine drug screen detects recent exposure to a class of drug; it does not diagnose a use disorder, does not measure impairment, and has false positives and negatives. The diagnosis is clinical, made on criteria from the history. A screen used without consent as surveillance also destroys the therapeutic alliance. ^[3]