USA Today: A new study reports using marijuana a few times per week is enough to physically alter critical brain structures.
"Just casual use appears to create changes in the brain in areas you don't want to change," said Hans Breiter, a psychiatrist and mathematician at the Northwestern University Feinberg School of Medicine in Chicago, who led the new study.
In his study, done in collaboration with researchers at Harvard University, scientists looked at the brains of 20 relatively light marijuana users and 20 people who did not use it at all. All 40 were college students in the Boston area.
The study found volume, shape and density changes in two crucial brain areas — the nucleus accumbens and the amygdala — involved with emotion and motivation and some types of mental illness. "This is a part of the brain you do not want to mess around with," Breiter said.
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