Rotterdam, The Netherlands: Subjects with a history of cannabis use, including near-daily consumption, possess no significant differences in white matter integrity when compared to those with no history of marijuana exposure, according to data published in the journal Addiction Biology.
A team of investigators from The Netherlands and from Australia performed MRIs to compare whole-brain white matter microstructure in a cohort of 39 near-daily cannabis users and 28 closely matched controls. The integrity of white matter microstructure is correlated with cognitive performance.
Consistent with prior studies, authors reported: “White matter microstructure did not differ between cannabis users and controls and did not covary with recent cannabis use, dependence severity, or duration of use.”
Investigators concluded, “These findings suggest that long-term near-daily cannabis use does not necessarily affect white matter microstructure.” Nonetheless, they cautioned that adolescents may be susceptible to possible changes in brain morphology..
Full text of the study, “The relation between cannabis use, dependence severity and white matter microstructure: A diffusion tensor imaging study,” appears in Addiction Biology. Additional information on cannabis and brain morphology is available from the NORML fact sheet, ‘Marijuana Exposure and Cognitive Performance.’