Background: Delta-9-tetrahydrocannabiphorol (Δ9-THCP) is a potent phytocannabinoid found naturally in the cannabis plant in small quantities. This cannabinoid is noted to potently bind to cannabinoid receptor 1 and cannabinoid receptor 2 and is reported to be highly psychoactive. A small amount of Δ9-THCP is found naturally, which led to its isolation and synthetic production. This isolate is beginning to be sold at dispensaries. Information on Δ9-THCP is sparse and case reports of adverse events add to the current literature.
Case presentation: This case report describes a patient who was brought into the emergency department with a self-inflicted stab wound to the chest after consuming 8 mg of Δ9-THCP. The patient was a regular user of standard tetrahydrocannabinol (THC) products from dispensaries and had no history of psychotic symptoms. The patient consumed the 8 mg just over 2 days prior to admission and noted psychotic symptoms for 48 h. The symptoms included depersonalization and a belief that he was already dead. A single dose of haloperidol 5 mg intravenous push was administered in the intensive care unit due to agitation. Afterwards, the patient refused all oral antipsychotics and the psychotic symptoms cleared prior to discharge.
Conclusion: The case adds to the evidence suggesting that Δ9-THCP is highly potent and psychoactive. Even experienced users of THC may have adverse effects to Δ9-THCP due to differences in binding and potency. Isolates of phytocannabinoids require caution prior to use.
Keywords: THCP; psychosis; substance use; suicidality; tetrahydrocannabiphorol.
© 2025 The Author(s). Psychiatry and Clinical Neurosciences Reports published by John Wiley & Sons Australia, Ltd on behalf of Japanese Society of Psychiatry and Neurology.