Substance intoxication, withdrawal and use disorders in youth — formative SAQs

SAQ 1 (10 marks)

A 16-year-old boy is brought by his mother after a six-month slide in school marks, withdrawal from his usual sport, and a new peer group. He is irritable and guarded in the interview. Taken alone, he admits daily cannabis use, smoking from age 13, failed efforts to cut down, and episodes of driving after using. He describes irritability, insomnia and loss of appetite when he runs out. His CRAFFT screen is positive on five items. He has low mood but no current suicidal plan. ^{[2] [3]}

1. Give the most likely diagnosis with the DSM-5 criteria that support it, and separate intoxication, withdrawal and the use disorder in this case. (3) ^[1]
2. Outline your screening, assessment and the framework you use to stratify him. (3) ^{[2] [3]}
3. Describe the stepped-care treatment plan, naming the first-line evidence-based interventions. (4) ^{[4] [5]}

Model answer — SAQ 1

(1) Diagnosis and the three states (3). The picture fits a cannabis use disorder, at least moderate. He meets multiple DSM-5 criteria across the clusters: impaired control (failed efforts to cut down, craving implied), social impairment (school decline, withdrawal from sport, new risky peer group), risky use (driving after using), and pharmacological change (tolerance implied and a withdrawal syndrome of irritability, insomnia and appetite loss on cessation). The three states are separable: he is not acutely intoxicated in clinic; he describes a cannabis withdrawal syndrome; and he meets criteria for the use disorder itself, which is the diagnosis. A urine drug screen is not required to make the diagnosis. ^[1]

(2) Screening and stratification (3). Screen every adolescent with a validated tool — CRAFFT for alcohol and other drugs, with two or more positive items signalling a likely problem (he scores five), or S2BI by past-year frequency. Confirm with a structured, confidential, multi-informant HEEADSSS interview: every substance, age of onset, route, frequency, consequences and attempts to stop, plus a mental state, self-harm, safeguarding and pregnancy assessment. The framework is SBIRT: screen, brief intervention, referral to treatment — and stratify by severity into brief intervention, specialist youth AOD input, or multidisciplinary care. ^{[2] [3]}

(3) Stepped care (4). His severity warrants specialist youth alcohol-and-other-drug input. First-line treatment is evidence-based psychosocial: motivational interviewing, cognitive behavioural therapy, family-based therapy and contingency management — the Cannabis Youth Treatment study (Dennis) and the Waldron review establish these as effective in adolescents. Address cannabis withdrawal with sleep, mood and craving management. Treat the comorbid low mood actively and reassess suicide risk at every visit. Build a relapse-prevention plan with a clearly named clinician for follow-up, and counsel openly on the cannabis-and-psychosis and educational-harm risks of early, heavy use. ^{[4] [5]}