Psych MEQs / SAQs · Addiction psychiatry — hallucinogen-related disorders
Hallucinogen-related disorders — bad trip, HPPD, and PAT interface (MEQ)
FRANZCP-style MEQ on classic psychedelic intoxication, talk-down care, dual formulation of psychosis, HPPD, and accurate reading of PAT trials versus recreational use.
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Target exams
Model answer
Reveal model answer
(i) Acute assessment and management. ABC and medical exclusion first (vitals, glucose already done; watch for adulterant toxicity, hyperthermia, trauma, MDMA co-toxidrome if history expands). Secure environment to prevent road injury. Low-stimulus setting, calm talk-down, continuous observation through expected peak; time-limited benzodiazepine (here lorazepam 1 mg orally) for severe panic/agitation when support alone is insufficient. Antipsychotic not automatic for every perceptual change. Do not start "hallucinogen detox" seizure protocols. Document substance timeline, capacity and risk.[1][2]
(ii) Psychosis risk and dual formulation. Acute persecutory content temporally linked to claimed LSD with relatively clear orientation favours substance-related intoxication/psychotic symptoms rather than proven lifelong primary schizophrenia on day one. Maternal uncle with schizophrenia elevates vulnerability and mandates honest risk counselling and longitudinal follow-up — dual formulation remains open if symptoms persist after washout. Family pressure for immediate lifelong depot is a trap; use timeline, collateral and planned review.[5]
(iii) HPPD definition and management. Re-experiencing of perceptual phenomena (trailing, geometric patterns) after cessation, with distress and occupational impairment, fits HPPD rather than ongoing intoxication. Validate; exclude alternative visual/neurological causes as indicated; advise ongoing abstinence from hallucinogens and ideally cannabis; treat secondary anxiety; evidence for specific anti-HPPD drugs is limited/case-level — avoid inventing a mandatory complex polypharmacy algorithm.[3][4]
(iv) PAT evidence interface. Protocolised trials (e.g. Goodwin: single 25 mg oral psilocybin superior to 1 mg control at 3 weeks on primary depression outcome in TRD under research conditions with support) are not equivalent to unsupervised microdosing. Explain screening, preparation, session support and integration; legal and safety limits in ANZ standard care; offer evidence-based depression pathways instead of colluding with illicit supply.[1][6]
(v) Disposition and harm reduction. Discharge only when MSE safe and supports available; written advice on set/setting, dose uncertainty/adulterants, no driving while residual effects, avoid use given family psychosis risk and HPPD, AOD brief intervention, dual-diagnosis or early-intervention follow-up, crisis contacts, ophthalmology/neurology thresholds if visual differential unclear.[1][3][5]
Common errors
- Treating classic psychedelic distress as alcohol withdrawal seizure detox.
- Lifelong schizophrenia label after a single linked episode without timeline.
- Equating PAT trial headlines with unsupervised microdosing scripts.
- Dismissing impairing post-cessation visual phenomena as trivial flashbacks.
- Missing injury risk (roads, heights) during the bad trip. [1][3][6]
Examiner notes
Full marks require medical exclusion plus talk-down ladder, dual formulation with family-risk counselling, accurate HPPD definition/management limits, precise PAT trial reading (25 mg signal under protocol, not DIY), and harm-reduction disposition. [1][3][6]
References
- [1]Johnson MW, Richards WA, Griffiths RR Human hallucinogen research: guidelines for safety J Psychopharmacol, 2008.PMID 18593734
- [2]Nichols DE Psychedelics Pharmacol Rev, 2016.PMID 26841800
- [3]Halpern JH, Pope HG Jr Hallucinogen persisting perception disorder: what do we know after 50 years? Drug Alcohol Depend, 2003.PMID 12609692
- [4]Martinotti G, Santacroce R, Pettorruso M, et al. Hallucinogen Persisting Perception Disorder: Etiology, Clinical Features, and Therapeutic Perspectives Brain Sci, 2018.PMID 29547576
- [5]Carbonaro TM, Bradstreet MP, Barrett FS, et al. Survey study of challenging experiences after ingesting psilocybin mushrooms: Acute and enduring positive and negative consequences J Psychopharmacol, 2016.PMID 27578767
- [6]Goodwin GM, Aaronson ST, Alvarez O, et al. Single-Dose Psilocybin for a Treatment-Resistant Episode of Major Depression N Engl J Med, 2022.PMID 36322843