A drug with psychotomimetic (also known as psychotogenic) actions mimics the symptoms of psychosis, including delusions and/or delirium, as opposed to just hallucinations. Psychotomimesis is the onset of psychotic symptoms following the administration of such a drug.
Some drugs of the opioid class have psychotomimetic effects. Particularly, mixed kappa receptor agonist mu receptor antagonist opioid analgesics can cause dose-related psychotomimesis. This adverse effect, incidence 1–2%, limits their use. Pentazocine and butorphanol fall under this opioid class.
There is evidence that cannabinoids are psychotomimetic, especially delta-9-tetrahydrocannabinol (THC). D'Souza et al. (2004) found that intravenous THC produced effects that resemble schizophrenia in both the positive symptoms (illusions, paranoia and disorganized thinking) and negative symptoms (apathy, anhedonia, alogia, asociality, avolition). Some types of cannabis may be more psychotomimetic than others, probably due to the action of cannabidiol (CBD), which inhibits P450 3A11's metabolic conversion of THC to 11-hydroxy-THC, which is four times more psychoactive.p. 39
Carl Sagan used the word "psychotomimetic" in his anonymous article "Mr.X" to describe the effects of cannabis, writing that "I smile, or sometimes even laugh out loud at the pictures on the insides of my eyelids. In this sense, I suppose cannabis is psychotomimetic, but I find none of the panic or terror that accompanies some psychoses."