"Casual marijuana use may come with some not-so-casual side effects.
For the first time, researchers at Northwestern University have analyzed the relationship between casual use of marijuana and brain changes – and found that young adults who used cannabis just once or twice a week showed significant abnormalities in two important brain structures.
The study’s findings, to be published Wednesday in the Journal of Neuroscience, are similar to those of past research linking chronic, long-term marijuana use with mental illness and changes in brain development. "
Utilizing magnetic resonance imaging (MRI), the researchers analyzed the participants’ brains, focusing on the nucleus accumbens (NAC) and the amygdala – two key brain regions responsible for processing emotions, making decisions and motivation. They looked at these brain structures in three different ways, measuring their density, volume and shape.
According to Breiter, all three were abnormal in the casual marijuana users.
“For the NAC, all three measures were abnormal, and they were abnormal in a dose-dependent way, meaning the changes were greater with the amount of marijuana used,” Breiter said. “The amygdala had abnormalities for shape and density, and only volume correlated with use. But if you looked at all three types of measures, it showed the relationships between them were quite abnormal in the marijuana users, compared to the normal controls.”
Because these brain regions are central for motivation, the findings from Northwestern help support the well-known theory that marijuana use leads to a condition called amotivation. Also called amotivational syndrome, this psychological condition causes people to become less oriented towards their goals and purposes in life, as well as seem less focused in general.
Given these eye-opening results, Breiter said that more research is needed to look into marijuana’s effects on the brain – even in those who use the drug only once or twice a month.
“We need to see what happens longitudinally,” Breiter said. “What happens as you follow people over time? What happens if they stop using – do these bad effects continue? What happens if you can intervene early?...My worry is we haven’t studied this compound and here we are looking to change legislation on it.”
Although Breiter’s team members did not examine the patients’ cognitive symptoms, they do believe that the brain abnormalities seen in their study could lead to substantial effects on brain development and behavior, especially given the young ages of the participants.
No comments:
Post a Comment