Alcohol, Not Cannabis, Associated with Changes in Brain Morphology 

May 25, 2021 at 01:00 pm by pj



According to a new study published in PubMed through the US National Institutes of Health and the Journal of Biological Psychiatry, alcohol consumption, but not cannabis use, is associated with changes in brain morphology.  The links to the study are below: 

The Effects of Alcohol and Cannabis Use on the Cortical Thickness of Cognitive Control and Salience Brain Networks in Emerging Adulthood: A Co-twin Control Study - Biological Psychiatry (  


The theory has been impairments with inhibitory control and its underlying brain networks are associated with substance misuse.  To study this theory, researchers with the University of Minnesota assessed the relationship between alcohol and cannabis exposure during young adulthood on brain morphology in a population-based sample of 436 twins aged 24 years.  Dimensional measures of cannabis use and alcohol use across emerging adulthood were measured.  These dimensional measures were frequency of use, density of brain cortexes, quantity of product consumed, and number of intoxications of use.   

From the data, the authors reported, “Greater alcohol, but not cannabis, misuse was associated with reduced thickness of prefrontal and frontal medial cortices, as well as the temporal lobe, intraparietal sulcus, insula, parietal operculum, precuneus, and parietal medial areas.”  

Neuroimaging research indicates that human’s intellectual ability is related to brain structure, including the thickness of the cerebral cortex. Investigators concluded: “No significant associations between cannabis use and thickness were observed. The lack of cannabis-specific effects is consistent with literature reviews, large sample studies, and evidence that observed cannabis effects may be accounted for by comorbid alcohol. 

“This study provides novel evidence that alcohol-related reductions in cortical thickness of control/salience brain networks likely represent the effects of alcohol exposure and premorbid characteristics of the genetic predisposition to misuse alcohol. The dual effects of these two alcohol-related causal influences have important and complementary implications regarding public health and prevention efforts to curb youth drinking.” 

The findings are consistent with those of several other studies – such as this 2017 study and this 2015 study – indicating that the use of alcohol, but not cannabis, is associated with negative changes in brain morphology. According to the findings of a literature review of 69 studies published in JAMA Psychiatry, “Associations between cannabis use and cognitive functioning in cross-sectional studies of adolescents and young adults are small and may be of questionable clinical importance for most individuals. Furthermore, abstinence of longer than 72 hours diminishes cognitive deficits associated with cannabis use. Results indicate that previous studies of cannabis youth may have overstated the magnitude and persistence of cognitive deficits associated with marijuana use.” 


This study destroys a strong perceived bias that legal products (alcohol, prescription drugs, etc.) are more safe than illegal products (cannabis, psychedelics, etc.).  As a society, we have begun looking at cannabis through the “lens” of science and data, rather than ideology and political lies and theater.  Through objective data, we are realizing that cannabis can be a safer alternative than alcohol for responsible adult consumption and as a prescribed or recommended medication.  

As cannabis becomes easier to study in the United States, we expect to see many more studies showing the efficacy of cannabis use for many medical reasons.  However, we also expect to see multiple studies on cannabis related to low dose THC cannabis being used as a daily health supplement.   The future of mass adoption of cannabis for wellness/health related reasons is coming.  As more countries legalize cannabis and the ideology of cannabis being a “bad drug” starts to fade with more objective scientific data, more people will use cannabis and see the benefits and safety of plant-based medicine firsthand.  


Michael C. Patterson, founder and CEO of U.S. Cannabis Pharmaceutical Research & Development of Melbourne, is a consultant for the development of the medical marijuana industry nationwide and in Florida. He serves as a consultant to Gerson Lehrman Group, New York and helps educate GLG partners on specific investment strategies and public policy regarding Medical Marijuana in the U.S. and Internationally. He can be reached at