Altered prefrontal and insular cortical thickness in adolescent marijuana users

Area of Science:

• Neuroscience
• Developmental Psychology
• Radiology

Background:

• Adolescence is a critical period for brain development, specifically cortical maturation.
• Limited data exists on the effects of marijuana (MJ) use on adolescent cortical development.
• Cortical thickness abnormalities can indicate disruptions in normal brain development.

Purpose of the Study:

• To investigate the impact of heavy marijuana use on cortical thickness in adolescents.
• To compare cortical thickness measures between adolescent marijuana users and non-using controls.

Main Methods:

• Utilized cortical-surface based techniques to analyze MRI scans from 18 heavy MJ-using adolescents and 18 controls.
• Employed FreeSurfer for cortical reconstruction and volumetric segmentation.
• Assessed group differences in cortical thickness using statistical difference maps, controlling for age and gender.

Main Results:

• Marijuana users exhibited decreased cortical thickness in the right caudal middle frontal, bilateral insula, and bilateral superior frontal cortices.
• Increased cortical thickness was observed in marijuana users in the bilateral lingual, right superior temporal, right inferior parietal, and left paracentral regions.
• Negative correlations were found between cannabinoid levels and frontal/lingual regions, and between age of onset and the right superior frontal gyrus in MJ users.

Conclusions:

• This study provides novel insights into cortical thickness alterations in adolescents with heavy MJ use.
• Findings align with previous research indicating abnormalities in prefrontal and insular regions.
• Reduced insular thickness may serve as a biomarker for heightened risk of substance dependence, and early MJ use may affect prefrontal cortical development.