Marijuana’s effects on the mammalian brain


A discussion on marijuana and its many derivatives has reached a new crescendo in the Belizean sphere. The potential of marijuana to wreak havoc can never be underestimated given that its inherent compounds can mimic the mammalian brain’s naturally occurring biochemicals.
Marijuana’s potentially detrimental impact on the developing brains of adolescents remains a key focus of research—particularly because of the possibility teenage users could go on to face a higher risk of psychosis.
The results show people who had consumed cannabis before age 18 developed schizophrenia approximately 10 years earlier than others. The higher the frequency of use, the data indicated, the earlier the age of schizophrenia onset.
Beat Lutz, a neurochemist at the University of Mainz, described the mechanisms by which the drug might produce deleterious effects in a young person’s brain. The main psychoactive compound in marijuana, tetrahydrocannabinol THC, disrupts the normal flow of signals among brain cells—a process normally regulated by chemicals called endocannabinoids. These compounds occur naturally in the body and activate a type of cellular docking site (called the cannabinoid type 1, or CB1, receptor) to “act like a circuit breaker,” Lutz says, keeping the brain’s level of signaling activity or “excitation” within a normal range. Too little endocannabinoid signaling results in excessive excitation of the nervous system, and this can promote anxiety disorders, impulsivity and epilepsy. Too much activity has the opposite effect and can promote depression, for example. Upsetting the information flows regulated by the endocannabinoid system has also been linked to psychosis.
THC acts differently from endocannabinoids. It does not break down rapidly in the body the way natural endocannabinoids do, Lutz says, noting this sustained activation causes serious wide-ranging disturbances in the brain. Low doses of THC may reduce anxiety but high doses can heighten it, and chronic overstimulation of CB1 receptors by THC shuts down the body’s natural endocannabinoid signaling system by eliminating the CB1 receptors from neurons, Lutz adds. Also, new research reveals mitochondria, the organelles within cells that generate energy for cellular metabolism, also have CB1 receptors. THC inhibits mitochondrial activity, reducing the cells’ vital energy supply, he says, citing a 2016 paper published in Nature. Perhaps most critically, he believes THC’s disruption of endocannabinoid signaling in the early teen brain can hinder key neurodevelopmental processes that involve the CB1 receptors, thereby impairing brain communication permanently.
The Mental Health Association of Belize stated in 2015 that “in our experience the use of mind-altering substances can and does have serious negative effects that exacerbate the underlying mental health and social problems that an individual might be facing. This is especially true for young people… For these reasons we believe that the official response should be such as to discourage use while at the same time expanding access to treatment and rehabilitation”.
Is cannabis addictive? There was a time when experts thought this was not the case.
But current evidence suggests that it can be – particularly if it’s used regularly – with about 10% of regular users estimated to have a dependence.
For some people who quit, there can be withdrawal symptoms, such as cravings, difficulty sleeping, mood swings, irritability and restlessness, according to the Royal College of Psychiatrists.
People end up having problems with relationships. It impacts on their ability to function at work. While some of this addiction may be psychological, experts say there is good evidence to suggest that THC itself can be physically addictive for some people.
Getting high on cannabis impairs memory and cognitive ability in the short term. And some of the effects of this, though mild and reversible, seems to remain for up to 20 days, the amount of time it takes for the drug to leave the system.
The debate on marijuana and its impact on Belizean Society is likely going to continue. Whatever direction Belizeans take on the issue, cannot escape the fact that marijuana contains varying quantities of psychoactive compounds.