Cannabis dampened the brain's reward response to music, but CBD offset this effect

Double-blind, placebo-controlled crossover study. 16 cannabis users inhaled cannabis with CBD, cannabis without CBD, and placebo across 3 sessions. fMRI measured brain responses to music vs. scrambled sound controls. Regions of interest identified from a meta-analysis of music-evoked reward and emotion.

This is one of the first studies to show that cannabis can dampen the brain's natural reward response to a pleasurable activity, which may help explain the motivational and anhedonia effects some users experience. The finding that CBD offsets this dampening adds to evidence that the CBD content of cannabis matters for its effects on reward processing.

The disconnect between subjective experience (wanting to listen more, enhanced perception) and objective brain measures (dampened reward and emotion circuitry) is striking. It suggests cannabis may alter the subjective evaluation of pleasure without actually enhancing the neural reward response, which has implications for understanding cannabis use patterns and motivation.

Small sample size (16 participants) limits statistical power and generalizability. All participants were existing cannabis users, so results may not apply to naive users. The cannabis preparations used specific THC and CBD doses that may not reflect real-world products. Music preference was not individualized.