To test how attentional bias and explicit liking are influenced by delta-9-tetrahydrocannabinol (THC) and whether these effects are moderated by cannabidiol (CBD).
Double-blind, randomised, within-subjects crossover study.
NIHR Wellcome Trust Clinical Research Facility at King’s College Hospital, London, United Kingdom.
46 infrequent cannabis users (cannabis use <1 per week).
Across four sessions, participants inhaled vaporised cannabis containing 10mg of THC and either 0mg (0:1 CBD:THC), 10mg (1:1), 20mg (2:1), or 30mg (3:1) of CBD, administered in a randomized order and counter-balanced across participants (a total of 24 order groups).
Participants completed two tasks: 1) Attentional Bias (AB), comparing reaction times towards visual probes presented behind 28 target stimuli (cannabis/food) compared with probes behind corresponding non-target (neutral) stimuli. Participants responding more quickly to probes behind target than non-target stimuli would indicate greater attentional bias to cannabis/food; 2) Picture Rating (PR), where all AB stimuli were rated on a 7-point pleasantness scale, measuring explicit liking.
During the AB task, participants were more biased towards cannabis stimuli in the 0:1 condition compared with baseline (mean difference=12.2, 95% confidence intervals [CIs]=1.20-23.3, d=0.41, p=0.03). No other significant AB or PR differences were found between cannabis and food stimuli between baseline and 0:1 condition (p>0.05). No significant CBD effect was found on AB or PR task performance at any dose (p>0.05). There was additionally no cumulative effect of THC exposure on AB or PR outcomes (p>0.05).
A double-blind, randomised, crossover study among infrequent cannabis users found that inhaled delta-9-tetrahydrocannabinol increased attentional bias towards cannabis in the absence of explicit liking, a marker of liability towards cannabis use disorder. At the concentrations normally found in legal and illegal cannabis, cannabidiol had no influence on this effect.
|Publication status||Accepted/In press - 7 Sept 2023|