Teen cannabis use disorder was linked to dulled brain responses to threatening situations

Increasing CUD symptomatology was associated with decreased responding to looming threat stimuli in regions including rostral frontal cortex, fusiform gyrus, and amygdala. This pattern was specific to cannabis use disorder; alcohol use disorder severity showed no relationship with threat responsiveness.

fMRI study of 87 adolescents (43 male) with varying CUD/AUD severity (45 above clinical cutoffs). Scanned during a looming threat task with threatening and neutral faces/animals that appeared to approach or recede.

Dulled threat responsiveness could have real-world consequences for adolescent safety and decision-making. The finding that this effect is specific to cannabis and not alcohol suggests a unique neurotoxic impact of cannabis on the developing threat processing system.

The amygdala and frontal cortex are critical for detecting and responding to danger. If adolescent cannabis use blunts these responses, it could affect risk assessment, social judgment, and emotional processing in ways that compound other known effects of cannabis on the developing brain.

Cross-sectional design cannot determine whether CUD caused the brain changes or whether pre-existing differences predispose to CUD. Relatively small sample. CUD and AUD severity were correlated, though the study controlled for this. Cannabis is not the only factor affecting these brain regions in adolescence.