Cannabis Dampens the Effects of Music in Brain Regions Sensitive to Reward and Emotion

Abstract

BackgroundDespite the current shift towards permissive cannabis policies, few studies have investigated the pleasurable effects users seek. Here, we investigate the effects of cannabis on listening to music, a rewarding activity that frequently occurs in the context of recreational cannabis use. We additionally tested how these effects are influenced by cannabidiol, which may offset cannabis-related harms.MethodsAcross 3 sessions, 16 cannabis users inhaled cannabis with cannabidiol, cannabis without cannabidiol, and placebo. We compared their response to music relative to control excerpts of scrambled sound during functional Magnetic Resonance Imaging within regions identified in a meta-analysis of music-evoked reward and emotion. All results were False Discovery Rate corrected (P<.05).ResultsCompared with placebo, cannabis without cannabidiol dampened response to music in bilateral auditory cortex (right: P=.005, left: P=.008), right hippocampus/parahippocampal gyrus (P=.025), right amygdala (P=.025), and right ventral striatum (P=.033). Across all sessions, the effects of music in this ventral striatal region correlated with pleasure ratings (P=.002) and increased functional connectivity with auditory cortex (right: P< .001, left: P< .001), supporting its involvement in music reward. Functional connectivity between right ventral striatum and auditory cortex was increased by cannabidiol (right: P=.003, left: P=.030), and cannabis with cannabidiol did not differ from placebo on any functional Magnetic Resonance Imaging measures. Both types of cannabis increased ratings of wanting to listen to music (P<.002) and enhanced sound perception (P<.001).ConclusionsCannabis dampens the effects of music in brain regions sensitive to reward and emotion. These effects were offset by a key cannabis constituent, cannabidol.

Dissociable effects of cannabis with and without cannabidiol on the human brain’s resting-state functional connectivity

“…Results have also been reported by Freeman et al (2017) on a music-listening fMRI task conducted on the same cohort, in the same scan session, as the resting-state data presented here. These showed that the Cann−CBD treatment significantly dampened responses to music in the auditory cortex and in limbic and striatal regions (amygdala, hippocampus and right ventral striatum), while the Cann+CBD treatment had little effect.…”

“…Approximately 30 minutes following drug administration, participants were situated in the MRI scanner and completed an approximately one-hour scanning session. The scanning session included standard anatomical scans, a music listening task (Freeman et al, 2017), a memory task and a resting-state scan (reported herein). Ratings of subjective effects using visual analogue scales (VAS) were administered immediately before the drug dosing, approximately 5 minutes after drug dosing and approximately 90 minutes after drug dosing (after the MRI scan).…”

“…These consisted of the following items: ‘Alert’, ‘Happy’, ‘Anxious’, ‘Paranoid’, ‘Mentally impaired’, ‘Stoned’, ‘High’, ‘Feel drug effect’, ‘Like drug effect’, ‘Dry mouth’, ‘Enhanced colour perception’, ‘Enhanced sound perception’, ‘Want to listen to music’, ‘Want food’ and ‘Want more cannabis’. Analysis of the VAS scores has been reported elsewhere (Freeman et al, 2017; Lawn et al, 2016). Following the MRI scan, subjects completed a number of additional behavioural tests and questionnaires; these are also fully reported elsewhere (Lawn et al, 2016).…”

“…In order to eliminate potential carry-over effects, scanning sessions were separated by wash-out periods of at least one week, which is more than three times the elimination half-life of THC (Hindocha et al, 2014(Hindocha et al, , 2015. Additional data from this study have been published elsewhere (Freeman, Pope, Wall, Bisby, Luijten, Hindocha, Mokrysz, Lawn, Bloomfield, et al, 2017;Lawn et al, 2016).…”

The acute effects of cannabidiol on the neural correlates of reward anticipation and feedback in healthy volunteers

“…Human research has shown that CBD can acutely alter neural, behavioural and psychological processes relating to reward, including effort sensitivity (Lawn et al, 2016), attentional bias to drug pictures (Hindocha et al, 2018; Morgan et al, 2010), drug consumption (Freeman et al, 2020; Morgan et al, 2013), neural response to music reward (Freeman et al, 2018) and levels of stress-induced social anxiety (Bergamaschi et al, 2011; Zuardi et al, 1993), without producing reinforcing or unpleasant side-effects (Haney et al, 2016). However, it is not known if CBD specifically acts on the human brain’s reward circuitry, or acts by another mechanism.…”