Impact of prenatal marijuana exposure on adolescent brain structural and functional connectivity and behavioural outcomes

Abstract

There has been an increase in the number of women using marijuana while pregnant. Previous studies have shown that children with prenatal marijuana exposure (PME) have developmental deficits in memory and decreased attentiveness. In this study we assess whether PME is associated with alterations in brain regional morphometry and functional and structural connectivity in adolescents. We downloaded behavioral scores and subject image files from the Adolescent Brain Cognitive DevelopmentSM (ABCD®) Study. 178 anatomical diffusion MRI files (88 PME, 90 age and gender matched controls) and 152 resting state functional MRI (rs-fMRI) files (76 PME, 76 controls) were obtained. Behavioral metrics based on the parent-reported child behavioral checklist (CBCL) were also obtained for each subject. The association of PME with 17 subscales of the CBCL was calculated. We assessed differences in brain morphometry based on voxel-based and surface-based morphometry in adolescents with PME versus controls. We also evaluated differences in structural and functional connectivity in adolescents for region-to-region connectivity and graph theoretical modeling. Interactions of PME and graph networks were assessed for impact on behavioral scores. Multiple comparison correction was performed as appropriate. Adolescents with PME had greater abnormal or borderline CBCL scores in 9 out of 17 subscales. There were no significant differences in voxel or surface-based morphometry, structural connectivity, or functional connectivity between PME and controls. However, there were significant differences in PME-graph network interactions with respect to behavioral scores. There were 3 structural PME-graph network interactions and 7 functional PME-graph network interactions that were significantly associated with behavioral scores. While this study was not able to confirm anatomical or functional differences between PME and unexposed pre-adolescent children, there were PME- brain structural and functional graph network interactions that were significantly associated with behavioral scores. This suggests that altered brain networks may underlie behavioral outcomes in adolescents with PME. More work needs to be conducted to better understand the prognostic value of brain structural and functional network measures in PME.