Three patients who regularly used only delta-8-tetrahydrocannabinol (Δ8-THC), a federally unregulated cannabis derivative, developed psychotic and paranoid symptoms severe enough to require admission to a university psychiatric hospital. The symptoms exceeded the severity of their previous psychiatric episodes and included new-onset violence and visual hallucinations in two patients, including one with no prior psychiatric history and one on a therapeutic antipsychotic dose. A third patient developed bizarre, fixed delusions of puppies dissolving in the bathtub. The report documents a temporal association between Δ8-THC use and psychosis, though conclusions are limited by reliance on self-reported use and possible confounding factors.
Dextromethorphan (DXM), a common over-the-counter cough suppressant, can cause psychosis when abused at high doses (over 1500 mg/day), producing delusions, hallucinations, and paranoia similar to phencyclidine (PCP). A case of severe DXM use disorder with psychotic disorder in a 40-year-old woman resolved only after treatment with an antipsychotic and mood stabilizer. DXM is not detected on standard urine drug screens, and its abuse may be an under-recognized cause of substance-induced psychosis. Clinicians should be aware of these psychiatric risks.