As a prelude to reviewing the relationship between cannabinoids and psychosis, a few important points need to be considered. First, the distinction between psychotic symptoms and a psychotic disorder such as schizophrenia needs to be considered. There are differences between these two outcomes with exposure to cannabinoids. Second, the symptoms of schizophrenia include not just positive symptoms (hallucinations, delusions, thought disorder, paranoia) but also negative symptoms (amotivation, social withdrawal, and emotional blunting) and cognitive deficits (impairments in memory, attention and executive function). Most of the literature has focused almost exclusively on positive symptoms. Third, in addition to its most active constituent Δ9-tetrahydrahydrocannabinol (Δ9-THC), cannabis contains several other cannabinoids including cannabidiol (CBD), cannabigerol, etc. [62]. Several reports suggest that the average Δ9-THC content of cannabis may be increasing [170]. The psychoactive effects of cannabis vary according to its Δ9-THC content. Cannabidiol has been shown to have anxiolytic and antipsychotic effects [126, 242] leading to the suggestion that CBD may offset some of the adverse effects of Δ9-THC. Just as there is variability in the Δ9-THC content of cannabis, there is variability
