A new study by the University of Texas at Dallas shows a link between the age that a person starts to use marijuana and severity of the long-term effects on the brain. Youth marijuana users are more susceptible to suffering from a permanently underdeveloped orbital frontal cortex in the brain, the area that controls decision-making and addiction. Researchers continue to call for more studies to be completed before the severity of the risks can be fully understood; meanwhile, youth marijuana users face long-term consequences to a still-unknown degree.
Long-Term Marijuana Use Linked To Abnormalities In Key Brain Region
November 11, 2014
By Marcia Cooper-White
Pot smokers say marijuana is a mind-expanding drug, but a new study conducted at The University of Texas at Dallas links heavy, long-term use of marijuana with smaller volume in the orbitofrontal cortex–a brain region associated with decision-making and addiction.
The same research shows that the brains of long-term users have greater connectivity in this region than do the brains of people who don’t use pot, although this connectivity seems to disappear over time with prolonged use. The research also shows that the earlier an individual starts using marijuana, the more pronounced the brain abnormalities.
Whether these brain abnormalities cause any mental or emotional deficits isn’t yet clear.
“The orbital frontal cortex is a key part of the brain’s reward system/network and instrumental in our motivation, decision-making and adaptive learning,” study leader Dr. Francesca Filbey, director of the university’s Center for BrainHealth and an associate professor in the university’s School of Behavioral and Brain Sciences, told The Huffington Post in an email. “As such, our finding that chronic marijuana users had smaller brain volume in the orbital frontal cortex, might manifest behaviorally making it difficult for them to change learned behavior.”
For the study, Filbey and her colleagues used MRI scanners to compare the brains of 48 adults who had smoked marijuana three times a day for 10 years, on average, to the brains of 62 non-users.