New Research Reveals Marijuana May Be Far Worse for the Brain Than We Thought

Man smoking marijuana cigarette

Man smoking marijuana cigarette | iStock.com/Pe3check

Researchers at the University of Osaka in Japan have concluded a study that suggests pot smoking is more harmful to our brains than we had realized. The study found that the cannabinoids that our body naturally produces, called “endocannabinoids,” are affected by marijuana in such a way that can drastically shape not only future neural network connections, but existing ones as well.

These compounds, which facilitate the bridging of brain connections to form neural circuits that are essential to virtually every aspect of cognitive function, were found to be less effective in lab rats who were subjected to THC. The study used fluorescent proteins to track the brain activity in newborn mice, and the findings offered some profound insight into how they developed mentally.

Rat among laboratory glasses

Rat among laboratory glasses | iStock.com/JanPietruszka

After the rats were injected with THC, the psychoactive compound in marijuana, they underwent a common occurrence called “synaptic pruning,” which not only meant that new connections and neural circuits were failing to form, but existing ones were essentially being deleted. This is common during human adolescence, in which the brain destroys inessential neural connections to streamline the network as a whole.

However, the pruning that took place in the lab rats subjected to THC was far more erratic and served not just to “streamline” the neural network, but seemed to destroy healthy, essential connections as well.

This is a big breakthrough because not only does it support the belief that marijuana slows down the “growth” of the brain, but it can also serve in a more destructive capacity by destroying connections that were previously in place. Much of this mental development occurs during adolescent years, which is why so many psychological disorders become apparent during this time as opposed to before or after. This time of development is a fragile one, and this finding that marijuana impacts the development and “neural pruning” in a way more destructive than previously thought means that the drug could be profoundly worse for teenagers than people of other ages.

MRI Image for Brain

MRI Image for Brain | iStock.com/Highwaystarz-Photography

The extent to which the drug is more or less impactful in teenage years than other times of life is not yet known, but the science behind this study and what we know about neural development thus far suggests that this experiment involving rats and injected TCH could open our eyes to what pot is really doing to our brains during development and after.