Laws regulating cannabis are rapidly changing globally, with Uruguay, Canada, and several US states now permitting recreational use. Concurrently, cannabis potency (of ∆9-tetrahydrocannabinol, THC) has increased in most parts of the world, and research suggests high-potency cannabis has a stronger association with risks of psychosis, cognitive impairment and cannabis addiction. However, recent evidence shows the second most prevalent compound in the cannabis plant, cannabidiol (CBD), has anti-psychotic and cognitively protective effects, and may help prevent or treat cannabis addiction.
This project explores the effects of CBD on THC-elicited negative effects in people with heavy problematic cannabis use.
The project will utilise multiple study designs:
An online survey of regular cannabis users, who will complete a series of cognitive assessments while using their own cannabis at home (Year 1).
A highly novel remote experimental study, where pharmacy-prepared cannabis with different doses of THC are delivered to participants along with a randomly-assigned blinded oral dose of CBD or placebo. Participants will self-administer study drugs and will complete cognitive tasks and clinical assessments via an online platform and videoconference (Year 2).
An experimental psychopharmacology study in heavy users in a controlled setting who will, over separate visits, be administered different doses of THC with or without a CBD pre-treatment (Year 2-3).
The successful candidate will join a world-leading experimental psychopharmacology unit. They will gain skills administering cognitive and psychological symptom assessments, experience designing and conducting experimental research with scheduled drugs, and will contribute to a rapidly emerging field of high policy relevance internationally.