Psych CASC / OSCE · Addiction psychiatry — dual diagnosis and integrated care
Explain dual diagnosis integrated care — CASC communication station
MRCPsych/FRANZCP-style communication station: explain co-occurring psychosis and cannabis use, integrated care, MI engagement, recovery hope, and safety-netting.
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Target exams
Station brief
Format. Communication station, approximately 7–10 minutes active time after reading. You are the psychiatry registrar in the early intervention / dual-capable community clinic. [1]
Candidate instructions. Explain dual diagnosis (psychosis and cannabis use), why care is integrated rather than "stop first then treat," outline medication and talking approaches including motivational work, address parents' fear that "he just needs tough love," and discuss recovery goals and safety. Check understanding. [1][2]
Candidate scenario
Your patient is 21 with first-episode psychosis and daily high-THC cannabis. He is not ready to quit. Parents say another service told them to bring him back only when he is clean. They ask: "Is the cannabis causing it? Should you stop his tablets until he stops smoking? How do you treat both?" [1][2]
Marking domains
- Empathy, structure, agenda-setting
- Clear definition of co-occurring problems without blame
- Explanation of integrated concurrent care vs sequential gatekeeping
- Cannabis–psychosis link (frequency/potency; relapse risk) without fatalism
- Motivational approach for ambivalence
- Medication purpose and monitoring in plain language
- Recovery hope (roles, housing, relationships) plus safety-net
- Checks understanding [1][2][3]
Reveal assessor key
Open. Thank them; name the time; ask main worries first. [1]
Explain dual diagnosis. "He has two active problems that feed each other: a psychotic illness and cannabis use. We treat both at the same time. Waiting for perfect abstinence before helping his mind usually means neither problem gets proper care." [1]
Cannabis link. "Daily high-potency cannabis is linked with higher risk of psychosis and, after illness starts, continued heavy use is linked with more relapses. Reducing or stopping is one of the highest-yield steps — but we help him get there with motivation and support, not rejection." [2]
Why not stop tablets. "Antipsychotic medicine reduces intensity of voices and fears for many people. Stopping it until urine is clean is not modern dual care." [1]
How we work with ambivalence. "We use motivational interviewing — collaborative conversations that help him find his own reasons to change, without arguing him into a corner." [3]
Care package. Shared plan: medication and physical monitoring, family education, substance counselling, practical support for study/work, crisis contacts. [1]
Close. Summarise, invite questions, written plan, review date, crisis numbers. [1]
References
- [1]Drake RE, Mueser KT, Brunette MF Management of persons with co-occurring severe mental illness and substance use disorder: program implications World Psychiatry, 2007.PMID 18188429
- [2]Schoeler T, Petros N, Di Forti M, et al. Effects of continuation, frequency, and type of cannabis use on relapse in the first 2 years after onset of psychosis: an observational study Lancet Psychiatry, 2016.PMID 27567467
- [3]Hettema J, Steele J, Miller WR Motivational interviewing Annu Rev Clin Psychol, 2005.PMID 17716083