Subjective and Physiological Effects of Oromucosal Sprays Containing Cannabinoids (Nabiximols): Potentials and Limitations for Psychosis Research

Cannabis use is associated with a spectrum of effects including euphoria, relaxation, anxiety, perceptual alterations, paranoia, and impairments in attention and memory. Cannabis is made up of approximately 80 different cannabinoid compounds, which have synergistic or antagonistic effects on the principle active ingredient in cannabis, delta-9-tetrahydrocannabinol (THC). The net overall effect of cannabis is thought to be related to the ratio of its composite constituents; in particular, the ratio of THC to cannabidiol (CBD). Since cannabinoids induce subjective and cognitive changes that share qualitative similarities with schizophrenia, cannabinoids have been used to model psychosis. Some limitations of cannabinoid models of psychosis include the relatively high variability in experiences between different individuals, the potential for inducing unwanted effects, such as toxic psychosis in study subjects, and the lack of data showing that effective anti-psychotic treatments can reverse the behavioural and cognitive/motor effects of cannabinoids. Nabiximols (Sativex®) is an oromucosal spray containing THC and CBD in an approximate 1:1 ratio. While not extensively studied, most studies confirm that nabiximols, despite the different route of administration and presence of CBD, have similar or slightly reduced subjective/cognitive effects compared to similar doses of oral THC. While the presence of CBD may have utility in some models, it is likely that the concentrations are not high enough to meaningfully affect those aspects important for psychosis research. This review suggests that while it may present an alternative to the use of oral THC, oromucosal nabiximols may not present substantial advantages for use in psychosis research.