A 22-year-old presents to the emergency department after smoking cannabis for the first time. He is severely anxious, experiences derealization, and believes the nurses are monitoring him for the government. His vital signs show tachycardia and mild hypertension. He has no prior psychiatric history. Urine toxicology is positive only for THC. What is the expected course?
- A Symptoms will typically resolve within hours as the drug is metabolised, with reassurance and benzodiazepines if needed ✓
- B He will require long-term antipsychotic therapy as cannabis-induced psychosis is irreversible
- C Haloperidol must be given immediately to prevent conversion to schizophrenia
- D Physostigmine should be administered to reverse anticholinergic cannabis toxicity
Correct answer: A. Symptoms will typically resolve within hours as the drug is metabolised, with reassurance and benzodiazepines if needed
Explanation
Cannabis intoxication can cause acute anxiety, paranoia, perceptual disturbances, and tachycardia, particularly with high-potency THC products. In the absence of a pre-existing psychotic disorder, these symptoms are substance-induced and typically resolve within a few hours to a day as THC is metabolised. Management is supportive with reassurance, a calm environment, and benzodiazepines for severe anxiety or agitation. Antipsychotics are generally not required for an acute intoxication state without persistent psychosis.
Reference: Kaplan & Sadock's Synopsis of Psychiatry, 11th ed.
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Written and medically reviewed by the StethoPrep medical team.