Insular Cortical Thinning and Altered Structural Connectivity in Chronic Cannabis Users: A High-Resolution Morphometry and Diffusion Tractography Study
Fouad Meraji Far, Hamid Reza Banafshe, Amir Ghaderi et al.
Chronic cannabis use is associated with thinning of the insular cortex, a brain region involved in craving and self-awareness, and with altered white matter connections between the insula and other brain areas. In a sample of 13 male chronic cannabis users compared to 13 male non-users, MRI scans showed bilateral insular thinning without volume loss, reduced total gray matter volume, and lower volumes in the brainstem, left amygdala, right thalamus, left cerebellar cortex, and right orbitofrontal gyrus. Tractography revealed reduced diffusivity in left insula–amygdala pathways and lower fractional anisotropy in several insula–cortical connections. These findings suggest that circuits supporting salience, interoception, and emotional valuation are preferentially disrupted, which may contribute to compulsive cannabis use.