Please use this link to access this publication: https://link.springer.com/article/10.1007/s00406-019-00978-2 Abstract Access to cannabis and cannabinoid products is increasing worldwide for recreational and medicinal use. Two primary compounds within cannabis plant matter, Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD), are both psychoactive, but only THC is considered intoxicating. There is significant interest in potential therapeutic properties of these cannabinoids and of CBD in particular. Some research has suggested that CBD may ameliorate adverse effects of THC, but this may be dose dependent as other evidence suggests possible potentiating effects of THC by low doses of CBD. We conducted a randomised placebo controlled trial to examine the acute effects...