Alcohol consumption is associated with negative changes in gray matter volume and in white matter integrity, while cannabis use is not, according to data published online ahead of print in the journal Addiction.
Investigators from the University of Colorado, Boulder and the Oregon Health & Science University evaluated neuroimaging data among adults (ages 18 to 55) and adolescents (ages 14 to 18). Authors identified an association between alcohol use and negative changes in brain structure, but identified no such association with cannabis.
“Alcohol use severity is associated with widespread lower gray matter volume and white matter integrity in adults, and with lower gray matter volume in adolescents,” they concluded. By contrast, “No associations were observed between structural measures and past 30-day cannabis use in adults or adolescents.”
Researchers acknowledged that their findings were similar to those of prior studies “suggesting that regionally specific differences between cannabis users and non-users are often inconsistent across studies and that some of the observed associations may actually be related to comorbid alcohol use.”
A 2015 brain imaging study published in The Journal of Neuroscience similarly reported that cannabis use was not positively associated with adverse changes in the brain, but that alcohol “has been unequivocally associated with deleterious effects on brain morphology and cognition in both adults and adolescents.”
Longitudinal data published in June in the British Medical Journal reported, “Alcohol consumption, even at moderate levels, is associated with adverse brain outcomes including hippocampal atrophy.”
An abstract of the study, “Structural Neuroimaging Correlates of Alcohol and Cannabis Use in Adolescents and Adults,” appears online here.