Just say 'know': How do cannabinoid concentrations influence users' estimates of cannabis potency and the amount they roll in joints?

Aims: (1) To determine whether measured concentrations of delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) in individuals' own cannabis predict their estimates of drug potency and actual titration; and (2) to ascertain if these effects are influenced by frequency of use and cannabis type. Design: Cross-sectional, naturalistic. Setting: Participants' own homes. Participants: A total of 247 cannabis users in the United Kingdom: 152 ‘recreational’ (1–24 days/month) and 95 ‘daily’ (≥25 days/month). Methods: Participants rated their own cannabis for its potency (1–10) and type (‘resin’, ‘herbal’, ‘skunk’) before smoking it in front of the researcher. The amount of cannabis (g) used in their joints was recorded and an additional sample was analysed for THC and CBD concentrations (%). Findings: THC concentrations were related negatively to the amount of cannabis used [unstandardized regression coefficient: b = −0.009, 95% confidence interval (CI) = −0.017, −0.002]. Potency estimates were predicted by increasing THC (b = 0.055, 95% CI = 0.020, 0.090) and decreasing CBD (b = −0.160, 95% CI = −0.284, −0.062), and both of these associations were mediated by cannabis type (THC: b = 0.018, 95% CI = 0.006, 0.037; CBD: b = −0.105, 95% CI = −0.198, −0.028). Potency estimates were more reflective of THC as frequency of use increased (b = 0.004, 95% CI = 0.001, 0.007) and were 7.3 times more so in daily (partial r = 0.381) than recreational users (r = 0.052). Conclusions: When using their own cannabis in a naturalistic setting, people titrate the amount they roll in joints according to concentrations of delta-9-tetrahydrocannabinol (THC) but not cannabidiol (CBD). Recreational users thus show poor understanding of cannabis potency

Cannabidiol Attenuates the Appetitive Effects of Δ9-Tetrahydrocannabinol in Humans Smoking Their Chosen Cannabis

Worldwide cannabis dependence is increasing, as is the concentration of Δ9-tetrahydrocannabinol (THC) in street cannabis. At the same time, the concentration of the second most abundant cannabinoid in street cannabis, cannabidiol (CBD), is decreasing. These two cannabinoids have opposing effects both pharmacologically and behaviorally when administered in the laboratory. No research has yet examined how the ratio of these constituents impacts on the appetitive/reinforcing effects of cannabis in humans. A total of 94 cannabis users were tested 7 days apart, once while non-intoxicated and once while acutely under the influence of their own chosen smoked cannabis on dependence-related measures. Using an unprecedented methodology, a sample of cannabis (as well as saliva) was collected from each user and analyzed for levels of cannabinoids. On the basis of CBD : THC ratios in the cannabis, individuals from the top and bottom tertiles were directly compared on indices of the reinforcing effects of drugs, explicit liking, and implicit attentional bias to drug stimuli. When intoxicated, smokers of high CBD : THC strains showed reduced attentional bias to drug and food stimuli compared with smokers of low CBD : THC. Those smoking higher CBD : THC strains also showed lower self-rated liking of cannabis stimuli on both test days. Our findings suggest that CBD has potential as a treatment for cannabis dependence. The acute modulation of the incentive salience of drug cues by CBD may possibly generalize to a treatment for other addictive disorders