Introduction
psychotic symptoms
ADVERSE EFFECTS
Several countries and US states have decriminalised or legalised cannabis use, and many permit the use of cannabis preparations for medicinal purposes. Over a similar period, the potency of cannabis, as indexed by its ∆9-tetrahydrocannabinol (THC) content, has been progressively increasing [As well as THC, cannabis also contains cannabidiol (CBD), which has very different effects. CBD does not impair cognitive performance, and has antipsychotic properties [These findings suggest that cannabis with a relatively high CBD:THC ratio may be less likely to have adverse effects than cannabis with a low CBD:THC ratio. The present study sought to investigate this by examining the acute effects of cannabis containing four different CBD:THC ratios (0:1, 1:1, 2:1 and 3:1) on cognitive performance and psychotic symptoms in healthy volunteers. These ratios were selected to reflect the CBD:THC ratios typically found in recreational cannabis, and in medicinal cannabis products [