A Preliminary Longitudinal fMRI Study of Neural Cannabis Cue-Reactivity in Adults Who Use Cannabis and Controls

BackgroundCannabis use is highly prevalent worldwide. Craving, a key feature of cannabis use disorder, drives continued and problematic cannabis use. Functional magnetic resonance imaging studies have shown that people who use cannabis exhibit heightened neural reactivity during exposure to cannabis cues, which were associated with self-reported cannabis craving and use problems. However, to date, long-term changes in neural cannabis cue-reactivity have not yet been examined. MethodsThe aim of this longitudinal study was to preliminairily investigate how neural cannabis cue-reactivity changes over time in adults who use cannabis regularly. Cannabis-related behavioral measures and neural reactivity to cannabis cues versus neutral cues were measured at baseline and 1-year follow-up in fourteen adults who use cannabis on a near-daily basis (age 22.4 ± 3.9 years, interval 367.1 ± 74.6 days) and sixteen non-using controls (age 22.2 ± 2.7 years, interval 353.8 ± 85.7 days). ResultsThe cannabis group exhibited significant reductions in neural cannabis cue-reactivity over time in default mode regions compared to controls, along with significant decreases in cannabis use disorder symptoms. Within the cannabis group, changes in cue-reactivity across default mode, frontal, visual, and limbic regions were associated with changes in self-reported cannabis craving, related problems, and withdrawal symptoms.ConclusionsLongitudinal reductions in neural cannabis-cue reactivity in the cannabis group track with improvements in cannabis use disorder symptoms. This suggests that neural cue-reactivity may be a meaningful biomarker of symptom change over time and could be used to monitor progress or treatment response in cannabis use disorder.