Biased Study Claims Chronic Use of Marijuana Impairs Brain’s Natural Response To Rewards
Posted by Marijuana Doctors on 07/18/2016 in Medical Marijuana Laws
A biased new study conducted at the University of Michigan, and recently published in Jama Psychiatry, claims that chronic recreational use of cannabis, over time, may impair the brain’s natural response to rewards.
As medical marijuana continues to go mainstream, there are many research programs and studies being conducted to scientifically understand the true potential of this alternatively-healing plant — however, every so often a study comes along still trying to establish a negative depiction of cannabis, with claims such as this one.
Over the course of four years, the study investigated and reviewed the brain scans of 108 individuals, in their early 20s. The researchers claim that the nucleus accumbens — the area of the brain that produces the pleasure chemical, dopamine — becomes smaller over time in those who reported frequent use of cannabis.
The study participants were required to play a game, that asked them to click a button when they saw an image on a screen. Some of the targets would provide monetary gains, others would provide monetary losses, or would not provide any reward whatsoever. The study aimed to trick the brain into activating the reward system as result of playing the virtual game. When the reward system is activated, the higher the amount of dopamine secreted, the more likely a person would be to repeat that behavior.
According to the report, the researches found that the cannabis users had a decreased amount of dopamine output over time, leading researches to conclude that cannabis may alter the brain’s reward system from the way it would operate in a natural environment.
“Marijuana is the most commonly used illicit drug in the United States and national surveys have shown that the perception of risk of harm from marijuana use has been decreasing over the past five years,” said Mary Heitzeg, who spearheaded the research. “Our findings challenge this growing perception that marijuana use is not harmful by demonstrating an association between marijuana use and changes in the functioning of the brain reward system over time.”
However, as 75% of the study participants, were men, and almost all were white Caucasians, opening the study findings to being questioned as inaccurate, and labelled biased.
A sample group of a 108 individuals, who are primarily white males, in their 20s, does not provide not a big enough sample pool to even remotely begin to even make conclusions, let alone educated guesses. There are numerous factors that could lead to the brain becoming less responsive, during the four-year duration of their testing. For instance, if an individual makes $50 an hour, yet has to sit for three hours in a room doing a test that at most can pay them $25 dollars per hour, the incentives of actually paying attention to the test, are trumped by the realization that their time, could be better spent elsewhere.
While this is purely speculative, it is merely one example and scenario that could impact the study’s findings. Another significant fact to consider, is the fact that all of the 108 individuals tested, were in their 20s, which denotes a “college demographic” of males, at an age and time in life when most individuals and their peer’s number one priority, is partying and getting lucky with the opposite sex — which implies that, if sex had been used as the motivator for the test’s “reward”, the results would likely have been the same with chronic-users, and non-users alike.
The key thing to remember when considering research and test data, is that until the study can be replicated on a large and demographically-varied scale, the results should be taken with a grain of salt.