Grey matter alterations associated with cannabis use: Results of a VBM study in heavy cannabis users and healthy controls

• Published in: NeuroImage (Orlando, Fla.) Fla.), 2012-02, Vol.59 (4), p.3845-3851
• Main Authors: Cousijn, Janna, Wiers, Reinout W., Ridderinkhof, K. Richard, van den Brink, Wim, Veltman, Dick J., Goudriaan, Anna E.
• Format: Article
• Language: English
• Subjects: Addictive behaviors; Adolescent; Adult; Brain - pathology; Brain research; Cannabis; Cannabis use disorder; Dependence; Drug addiction; Drug use; Ecstasy; Female; Humans; Magnetic Resonance Imaging; Male; Marijuana; Marijuana Abuse - complications; Morphology; MRI; Neuroimaging; NMR; Nuclear magnetic resonance; Organ Size; R&D; Research & development; Severity of Illness Index; Standard deviation; Studies; VBM; Young Adult
• ISSN: 1053-8119; 1095-9572
• DOI: 10.1016/j.neuroimage.2011.09.046

Cannabis abuse is related to impairments in a broad range of cognitive functions. However, studies on cannabis abuse in relation to brain structure are sparse and results are inconsistent, probably due to differences in imaging methodology, severity of cannabis abuse, and use of other substances. The goal of the current MRI study was to investigate brain morphology related to current and lifetime severity of cannabis use and dependence in heavy cannabis users without intensive use of other illicit drugs. Voxel-based morphometry was used to assess differences in regional grey and white matter volume between 33 heavy cannabis users and 42 matched controls. Within heavy cannabis users, grey and white matter volume was correlated with measures of cannabis use and dependence. Analyses were focused a priori on the orbitofrontal cortex, anterior cingulate cortex, striatum, amygdala, hippocampus, and cerebellum, regions implicated in substance dependence and/or with high cannabinoid receptor-1 concentrations. Regional grey matter volume in the anterior cerebellum was larger in heavy cannabis users. Within the group of heavy cannabis users, grey matter volume in the amygdala and hippocampus correlated negatively with the amount of cannabis use or dependence. No associations were found between white matter volume and measures of cannabis use or dependence. These findings indicate that associations between heavy cannabis use and altered brain structure are complex. Differential patterns of structural changes for various cannabis use levels imply that alterations in brain structure are associated with specific characteristics of cannabis use and dependence. ► Cerebellum grey matter volume is larger in cannabis users compared to controls. ► Reduced amygdala grey matter volume correlates with cannabis dependence. ► Reduced hippocampus grey matter volume correlates with weekly cannabis use. ► The association between cannabis use and brain structure is complex.