People at risk for cannabis use disorder showed more fluid and unstable brain connectivity patterns on fMRI

At-risk individuals (n=39) spent more time in a brain state with higher within-network and reduced between-network connectivity across subcortical, sensory-motor, visual, cognitive-control, and default-mode networks compared to controls (n=55). Globally, at-risk individuals had more meta-states, more transitions between them, and longer distances traveled in state space, indicating greater dynamic range and fluidity of brain connectivity.

Resting-state fMRI comparing 39 individuals at risk for CUD to 55 controls, stratified by CUDIT-R scores. Dynamic functional connectivity estimated using independent component analysis, sliding-time window correlations, and cluster/meta-state indices.

Most brain imaging studies of cannabis use examine static connectivity. This dynamic approach reveals that CUD risk is associated with unstable, hyperfluid brain states that may reflect difficulty maintaining stable network engagement, a finding invisible to traditional analyses.

If unstable brain connectivity is a marker of CUD vulnerability, dynamic fMRI could potentially identify at-risk individuals before problematic use develops. It also suggests that CUD risk involves fundamental changes in how the brain transitions between functional states.

Cross-sectional design cannot determine whether connectivity changes precede or result from cannabis use. Self-report screening tool for CUD risk. Relatively small sample size. Cannot control for all potential confounders including other substance use.