Debates on whether or not marijuana makes the brain shrink, apparently, are still heating up. According to a new study, the use of cannabis does not directly affect your brain volume.
TIME reports that a new research published in the journal JAMA Psychiatry explains the difference of the brain volumes among siblings - both pot-users and non-users.
As opposed to what they have hypothesized, researchers found out that there isn't any significant change done on the brain that has been linked to cannabis use.
For the study, researchers investigated a large group of siblings from age 22 to 35. 262 out of 483 participants reported they have used cannabis with some admitting even just once. The siblings were then paired into three different cases: siblings who don't use marijuana, siblings who both use marijuana, and a pair which one sibling uses marijuana and the other doesn't.
Results show that although marijuana users generally have smaller volumes on the left amygdala (a part of the brain responsible for emotional processing), researchers confirmed that these differences are still normal.
In contrary to what was expected, authors of the study found similar volumes of amygdala among sibling pairs where one uses cannabis and the other doesn't. The researchers concluded that they have "found no evidence for the casual influence of cannabis exposure on amygdale volume."
"Our study suggests that cannabis use, or at least the simple index of it that we used, does not directly impact changes in brain volumes," said Washington University School of Medicine associate professor Arpana Agrawal, one of the study's authors. "Instead, any relationship that we did see between cannabis use and brain volumes was due to predisposing factors that influence both cannabis use and brain volumes."
Researchers suggest other factors such as genetics or the environment as significant factors among differences in brain volumes. Further studies, however, still needs to be conducted in showing the effects of cannbis into a person's brain.
