The brain’s cortical thickness is a metric used to measure how thick the layers are in the cerebral cortex.
Cortical thickness gives an idea of a person’s cognitive abilities; it can give doctors and scientists an idea if there is any disease such as Alzheimer’s or Parkinson’s, and it can also determine if there is some type of brain damage.
In the past, prohibitionists loved to say that cannabis would cause brain damage but new studies now show that alcohol does, while cannabis doesn’t. The latest study of this kind revealed that alcohol impacts cortical thickness among young people and no impact was seen among those who used cannabis.
For the study, researchers analyzed the association between cannabis and alcohol exposure in the brains of young adults. They took a sample size using 436 twins, all of whom were 24 years of age. They then assessed the frequency, quality, density, and level of intoxication occurred after consuming both alcohol and marijuana, and after that they gathered data to check if marijuana use had an effect on cortical thickness which was measured through magnetic resonance imaging.
The researchers selected cannabis and alcohol-consuming twins for subjects so that they could assess what the impacts were, if any, of two different substances on them. “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,” writes the study.
“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,” says the researchers.
“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.”
Consistent With Previous Studies
It is becoming a known fact that alcohol causes brain damage while cannabis does not, and there are studies to back up these claims. Another study from 2017 conducted by researchers from Oregon Health & Science University together with the University of Colorado analyzed neuroimaging data taken from adults aged 18 through 55, as well as adolescents aged 14 through 18. The investigators determined that there was a link between alcohol consumption and changes observed in terms of brain structure but they found no causation among those who consumed 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,” the study concludes. On the other hand: “No associations were observed between structural measures and past 30-day cannabis use in adults or adolescents.”
Additionally, the researchers made it clear that their findings were consistent with older 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.”
There are more studies, too. One from 2015 conducted by researchers at the University of Colorado and the University of Louisville in Kentucky analyzed the brain morphology of adolescent and adult subjects who were daily cannabis users and compared them to non-users. They specifically looked for changes among their nucleus accumbens, hippocampus, amygdala, and cerebellum.
The researchers said they found “no statistically significant differences… between daily users and nonusers on volume or shape in the regions of interest”. This was observed after they checked for their alcohol consumption.
“The results indicate that, when carefully controlling for alcohol use, gender, age, and other variables, there is no association between marijuana use and standard volumetric or shape measurements of subcortical structures,” write the researchers.
Cannabis Actually Protects The Brain
Cannabis use doesn’t just not cause any impact on the brain; it actually protects it, says many studies.
One study from 2017 conducted by researchers from the University of Bonn and the Hebrew University revealed that consuming regular doses of low THC can help prevent the brain from slowing down, which is normally caused by aging. The animal study involved testing mice of various ages: 2 months, a year, and 18 years old every day, while administering them with THC for a month. They were then tested based on their capability to recognize objects familiar to them, and to navigate water mazes.
The results, which were also similarly observed in human trials, revealed that younger mice performed superbly when they were sober though they tended to show struggles when they were on THC. Meanwhile, the older mice struggled with their tasks but this was expected since they had older brains. What was interesting was that they found that the older mice saw a boost in performance when they were given THC infusions, leading their performance to be as better as the mice who weren’t given any THC at all.
“Together, these results reveal a profound, long-lasting improvement of cognitive performance resulting from a low dose of THC treatment in mature and old animals.”
“If we can rejuvenate the brain so that everybody gets five to ten more years without needing extra care then that is more than we could have imagined,” said Andras Bilkei-Gorzo, one of the study’s co-authors, to The Guardian.
So there – even more studies proving the benefits of cannabis for the brain. So put down that bottle, and get using!