Cannabidiol does not attenuate acute delta-9-tetrahydrocannabinol-induced attentional bias in healthy volunteers: A randomised, double-blind, cross-over study

Addiction. 2024 Feb;119(2):322-333. doi: 10.1111/add.16353. Epub 2023 Oct 11.

Abstract

Aims: To test how attentional bias and explicit liking are influenced by delta-9-tetrahydrocannabinol (THC) and whether these effects are moderated by cannabidiol (CBD).

Design: Double-blind, randomised, within-subjects cross-over study.

Setting: NIHR Wellcome Trust Clinical Research Facility at King's College Hospital, London, United Kingdom.

Participants/cases: Forty-six infrequent cannabis users (cannabis use <1 per week).

Intervention(s): Across four sessions, participants inhaled vaporised cannabis containing 10 mg of THC and either 0 mg (0:1 CBD:THC), 10 mg (1:1), 20 mg (2:1) or 30 mg (3:1) of CBD, administered in a randomised order and counter-balanced across participants (a total of 24 order groups).

Measurements: Participants completed two tasks: (1) Attentional Bias (AB), comparing reaction times toward 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.

Findings: During the AB task, participants were more biased toward 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).

Conclusions: A double-blind, randomised, cross-over study among infrequent cannabis users found that inhaled delta-9-tetrahydrocannabinol increased attentional bias toward cannabis in the absence of explicit liking, a marker of liability toward cannabis use disorder. At the concentrations normally found in legal and illegal cannabis, cannabidiol had no influence on this effect.

Trial registration: ClinicalTrials.gov NCT05170217.

Keywords: CBD; THC; attentional bias; cannabidiol; cannabis; cannabis use disorder; delta-9-tetrahydrocannabinol.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Attentional Bias*
  • Cannabidiol* / pharmacology
  • Cannabinoid Receptor Agonists
  • Cannabis
  • Cross-Over Studies
  • Double-Blind Method
  • Dronabinol* / adverse effects
  • Hallucinogens
  • Humans

Substances

  • Cannabidiol
  • Cannabinoid Receptor Agonists
  • Dronabinol
  • Hallucinogens

Associated data

  • ClinicalTrials.gov/NCT05170217