Delta-8-THC association with psychosis: A case report with literature review

Cannabis (Δ⁹-THC) is the most commonly consumed illicit drug. The Agricultural Improvement Act of 2018 removed hemp, a strain of Cannabis sativa, as a controlled substance. This law allowed the plant to be processed into its components, which contain <0.3% Δ⁹-THC. As a result, delta-8-tetrahydrocannabinol (Δ⁸-THC), a federally unregulated substance, grew in popularity in 2020. Δ⁸-THC is readily available in most gas stations or head shops and may be considered harmless by patients. However, an increasing number of patients admitted for psychiatric hospitalization report use, with limited literature on the effects.

This case report describes three individual cases of patients who required admission to a university psychiatric hospital after the regular use solely of Δ⁸-THC. All three patients developed psychotic and paranoid symptoms concurrently with the use of Δ⁸-THC, with a severity exceeding their previous historical presentations. The presenting psychotic symptoms were also atypical for all three patients. New-onset violence and visual hallucinations were noted in two of the patients, one patient with no previous psychiatric history and one patient while on a therapeutic dose of his antipsychotic. In the third case, a new onset of bizarre, fixed delusions of puppies dissolving in the bathtub developed.

This report adds to the limited body of evidence on Δ⁸-THC documenting a temporal association between Δ⁸-THC use and the development of psychotic symptoms. A strong body of research already correlates the continued use of Δ⁹-THC with psychosis, and Δ⁸-THC acts at the same CB₁ and CB₂ receptors as Δ⁹-THC. Therefore, it is hypothesized that Δ⁸-THC may have similar adverse psychiatric effects as Δ⁹-THC. These conclusions are not without speculation, due to the need for self or collateral-reporting of Δ⁸-THC use as urine drug screening cannot distinguish Δ⁸-THC from Δ⁹-THC, and the patients' symptoms could be explained by medication non-adherence and primary psychotic disorders. However, physicians should be encouraged to gather a specific history of Δ⁸-THC use and treat patients with Δ⁸-THC-related intoxication and symptoms.