Impact of cannabis use on prefrontal and parietal cortex gyrification and surface area in adolescents and emerging adults

•We compare gyrification and surface area in prefrontal and parietal cortex in young cannabis users and controls.•Frequent cannabis use was associated with reduced gyrification in prefrontal subregions.•Reduced gyrification in cannabis users was associated with poorer performance.•Sensitive periods during neurodevelopment may be affected by frequent cannabis use.

BackgroundRegions undergoing maturation with CB1 receptors may be at increased risk for cannabis-induced alterations. Here, we examine the relationships between cannabis use and prefrontal (PFC) and inferior parietal gyrification and surface area (SA) in youth.MethodsParticipants included 33 cannabis users and 35 controls (ages 18–25). Exclusions included co-morbid psychiatric/neurologic disorders and heavy other drug use. Multiple regressions and Pearson r correlations examined the effects of cannabis use on gyrification, SA and cognition.ResultsCannabis use was associated with decreased gyrification in: ventral-medial PFC (RH: [FDR corrected p = .02], LH: [FDR corrected p = .02]); medial PFC (RH: [FDR corrected p = .02], LH: [FDR corrected p = .02]); and frontal poles (RH: [FDR corrected p = .02], LH: [FDR corrected p = .02]). No differences were observed in bilateral hemispheres, PFC, dorsolateral, ventrolateral, or inferior parietal ROIs. Cannabis use was associated with marginally decreased SA in left: medial PFC [FDR corrected p = .09], and ventral lateral PFC: [FDR corrected p = .09]. In cannabis users, increased gyrification was associated with improved working-memory performance in right medial (p = .003), ventral-medial (p = .03), and frontal pole ROIs (p = .007).ConclusionsCannabis use was associated with reduced gyrification in PFC regions implicated in self-referential thought and social cognition. Results suggest that these gyrification characteristics may have cognitive implications.