Research Shows that Long-Term Cannabis Use Impacts Reward System

Scientists discovered that people who had smoked marijuana for a very long time had more activity in certain regions of the brain that contribute to the reward system. The co-author of the study, Dr. Francesca Filbey, of the School of Behavioral and Brain Sciences at the University of Texas at Dallas, as well as some of her co-workers, released their results in the journal Human Brain Mapping.

Although cannabis is the most utilized illegal drug in the United States, with about 22.2 million users just in the last month, more and more states have been legalizing marijuana, not just for recreational purposes, but also for medical purposes. But regardless of the growth in cannabis legalization, Dr. Filbey and colleagues state that there is not much information when determining issues the drug might cause in the future.

Albeit just a small amount of studies have looked into how cannabis impacts the neural circuits of the brain to impact cravings, some studies have indicated that the reward system plays a role in this. The reward system involves various brain regions that let out dopamine, a neurotransmitter that controls the reward and pleasure centers, in response to certain signals.

To further look into how cannabis use might impact the reward system, the team registered fifty-nine daily, long-term cannabis users, who have been using the drug for about twelve years, along with seventy peopled who do not use marijuana. Both groups had been pot in front of a display of visual cues. These included cannabis-associated images, such as joints, bongs, pipes, etc. There were also fruits presented such as bananas, apples, grapes.

The scientists state that fruit is a reward cue in it of itself since it is “inherently salient and represented in the brain’s reward system.” By looking at the brain using functional magnetic resonance imaging (fMRI), scientists saw that the cannabis smokers had the same brain activity as the entire group did when they saw both cues.