Scientists show that exposure to cannabis doesn’t alter the brain

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The brain’s morphology is not affected by cannabis exposure

Two independent studies have come to the same conclusion – cannabis does not alter the brain. The findings are significant and will help to counter the unfounded arguments that exposure to cannabis can have a negative impact on the younger population.

One study was conducted by the University of Pennsylvania through its Perelman School of Medicine. Researchers compared brain scans of consumers who were broken down into two groups – occasional users and frequent users. The latter was defined as someone who consumes more than three times a week. All of the subjects were from 14 to 22 years old.

The researchers concluded, “There were no significant differences by cannabis group in global or regional brain volumes, cortical thickness, or gray matter density, and no significant group by age interactions were found. Follow-up analyses indicated that values of structural neuroimaging measures by cannabis group were similar across regions, and any differences among groups were likely of a small magnitude.”

They added, “In sum, structural brain metrics were largely similar among adolescent and young adult cannabis users and non-users.”

In another study, researchers with the University of Colorado at Boulder looked at magnetic resonance imaging (MRI) scans of 28 cannabis users who were over 60 years of age. Those scans were compared to matched controls and the test subjects identified themselves as individuals who had consumed marijuana each week for 24 years or more.

That study revealed that long-term exposure to cannabis “does not have a widespread impact on overall cortical volumes while controlling for age, despite over two decades of regular cannabis use on average. This is in contrast to the large, widespread effects of alcohol on cortical volumes that might be expected to negatively impact cognitive performance.”

The researchers added, “The current study was able to explore cannabis use in a novel older adult population that has seen recent dramatic increases in cannabis use while controlling for likely confounding variables (e.g., alcohol use). The participants in this study were generally healthy and highly educated, and it is in this context that cannabis use showed limited effects on brain structural measures or cognitive performance.”

Science once again proves victorious over hearsay and another myth is busted.


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