• Australia has one of the highest marijuana prevalence rates in the world and socio-political discussions rage about the legalisation of marijuana for medical and scientific purposes.

    While compounds within marijuana hold therapeutic potential, prolonged and heavy recreational use is associated with adverse effects on the brain. Emerging evidence suggests that the extent to which brain-related harms manifest depends on interactions between the two primary constituents of cannabis plant matter: delta-9-tetrahydrocannabinol (THC) which is psychotogenic and neurotoxic; and cannabidiol (CBD) which has purported neuroprotective properties and may offset the adverse effects of THC. However, there is a lack of evidence regarding whether these harms can be minimised by modifying the relative ratios of THC and CBD contained in marijuana. These current gaps in knowledge raise significant ethical issues for health care providers seeking evidence-based recommendations.

    This project will be the first naturalistic human examination of the links between prolonged exposure to various compounds within marijuana, brain health, and associated cognitive and psychological factors.