The dark side of "legal highs": A case of psychosis in polysubstance use - A young psychonaut's perspective (2026)

Background: Hexahydrocannabinol (HHC) is a semi-synthetic cannabinoid increasingly used as a legal alternative to Δ9-THC and Δ8-THC. Despite its growing popularity, its pharmacological profile and psychotropic effects in humans are not well studied.
Case Summary: This report details the case of an 18-year-old male with a history of polysubstance use who experienced an acute psychotic episode following the use of HHC during a period of abstinence. The patient consumed HHC while on a solo trip in East Europe and subsequently developed symptoms including auditory-visual distortions, persecutory delusions, alongside mixed-state mood features, exacerbated by the concurrent use of Pervitin. The subjective experience described by the patient interestingly highlights some dissociative-like features, that he spontaneously related to ketamine. The patient was treated with Risperidone, which effectively managed his acute symptoms within 10 days. However, some mild perceptual alterations persisted post-recovery.
Conclusions: This case study highlights the potential for acute psychiatric complications following polysubstance use. In particular, it emphasizes the risks associated with semi-synthetic cannabinoids in individuals with a history of substance use disorders and mental health vulnerabilities. The psychotogenic potential of methamphetamine must be acknowledged as a significant contributing factor in polydrug use, even when combined with seemingly benign substances like HHC. [Author's abstract]