The presence of cannabidiol (CBD) in cannabis may alter cannabinoid pharmacokinetics, however previous research has produced mixed results. Furthermore, no prior research has explored how cannabinoid pharmacokinetics are moderated by age. Using vaporised and inhaled cannabis, we aimed to (1) examine the effect of CBD on the plasma concentration of delta-9-tetrahydrocannabinol (THC) and its...
Global shifts towards the liberalisation of cannabis policies have increased the potency of cannabis products, alongside their accessibility, diversity, and the number of inexperienced cannabis consumers. There is a lack of systematic evidence on the subjective effects of cannabis' main psychoactive compound, Δ9-tetrahydrocannabinol (THC). We systematically reviewed and meta-analysed data from...
Abstract Background Cannabis is one of the most widely used psychoactive substances in the world and is increasingly investigated as a treatment for neuropsychiatric conditions. Cannabis contains delta-9-tetrahydrocannabinol (THC), which is thought to underlie its main psychoactive effects, and cannabidiol (CBD), which has been proposed to modulate the effects of THC on the brain. Both have...
Abstract Background Cannabis, and its main psychoactive compound tetrahydrocannabinol (THC), may alter the brain’ s reward system both acutely and over time. The endocannabinoid and reward systems mature during adolescence and adolescents may therefore respond differently to acute cannabis exposure compared with adults. Despite this, no previous functional magnetic resonance imaging (fMRI)...
Adolescence is a time of rapid neurodevelopment and the endocannabinoid system is particularly prone to change during this time. Cannabis is a commonly used drug with a particularly high prevalence of use among adolescents. The two predominant phytocannabinoids are Delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), which affect the endocannabinoid system. It is unknown whether this...
RATIONALE: Attentional bias to drug-related stimuli is hypothesised to contribute towards addiction. However, the acute effects of Δ9-tetrahydrocannabinol (THC) on attentional bias to cannabis cues, the differential response in adults and adolescents, and the moderating effect of cannabidiol (CBD) are unknown. OBJECTIVES: Our study investigated (1) the acute effects of vaporised cannabis on...
Cannabis potency (concentration of Δ-9-Tetrahydrocannabinol) has been associated with risks of adverse mental health outcomes and addiction but no studies have triangulated evidence from self-report and objective measures of cannabis potency. We hypothesised that users of high potency cannabis would have higher levels of (a) anxiety, (b) depression and (c) psychosis-like symptoms (d) cannabis...
BACKGROUND/AIM: Cannabis use is highly prevalent in adolescents; however, little is known about its effects on adolescent brain function. METHOD: = 70, 35 adolescents/35 adults). Pre-registered analyses examined the connectivity of seven major cortical and sub-cortical brain networks (default mode network, executive control network (ECN), salience network, hippocampal network and three striatal...
Abstract Background and Aims Long‐term harms of cannabis may be exacerbated in adolescence, but little is known about the acute effects of cannabis in adolescents. We aimed to (i) compare the acute effects of cannabis in adolescent and adult cannabis users and (ii) determine if cannabidiol (CBD) acutely modulates the effects of delta‐9‐tetrahydocannabinol (THC). Design Randomised, double‐blind,...
Cannabis potency, defined as the concentration of Δ9-tetrahydrocannabinol (THC), has increased internationally, which could increase the risk of adverse health outcomes for cannabis users. We present, to our knowledge, the first systematic review of the association of cannabis potency with mental health and addiction (PROSPERO, CRD42021226447). We searched Embase, PsycINFO, and MEDLINE (from...
Abstract Background and objective Cannabis use during adolescence is common. Cannabis use and identity are thought to influence one another. This study aimed to examine what London-based adolescents (aged 16-17 years) think about cannabis use, its relationships with identity, and its benefits and harms. Method Three semi-structured focus groups interviews were conducted, two with adolescents...
BACKGROUND: Preclinical and human studies suggest that adolescent cannabis use may be associated with worse cognitive outcomes than adult cannabis use. We investigated the associations between chronic cannabis use and cognitive function in adolescent and adult cannabis users and controls. We hypothesised user-status would be negatively associated with cognitive function and this relationship...
Background: Preclinical and human studies suggest that adolescent cannabis use may be associated with worse cognitive outcomes than adult cannabis use. We investigated the associations between chronic cannabis use and cognitive function in adolescent and adult cannabis users and controls. We hypothesised user-status would be negatively associated with cognitive function and this relationship...
The recent liberalisation of cannabis regulation has increased public and scientific debate about its potential benefits and risks. A key focus has been the extent to which cannabidiol (CBD) might influence the acute effects of delta-9-tetrahydrocannabinol (THC), but this has never been reviewed systematically. In this systematic review of how CBD influences the acute effects of THC we...
receptor. Acutely, cannabis and THC produce a range of effects on several neurocognitive and pharmacological systems. These include effects on executive, emotional, reward and memory processing via direct interactions with the endocannabinoid system and indirect effects on the glutamatergic, GABAergic and dopaminergic systems. Cannabidiol, a non-intoxicating cannabinoid found in some forms of...
Adolescence is a critical period of brain development during which the endocannabinoid system continues to mature. These developmental changes may contribute to age-related differences in the association between cannabis use and large-scale functional network organisation, yet this association remains incompletely characterised. We hypothesised that regular cannabis use would be associated with...