A new study, conducted by a team of experts from the Massachusetts General Hospital and Harvard Medical School, shows that repeated marijuana smoking results in two neural regions being misshapen or enlarged, according to a report from NBC News. The two affected regions -- the right amygdala and left nucleus accumbens -- are said to be key to emotions and motivation.
The research analyzed 40 individuals between the ages of 18 and 25 years old. Twenty were current marijuana users -- using marijuana at least once a week -- and 20 were not. Researchers used an MRI machine to assess the brains of all individuals and found that the more marijuana a person consumed, the more damaged these neural areas would become.
The report states,
"Among the pot partakers, scientists measured differences in the sizes and shapes of their nucleus accumbens, which has a role in pleasure and reward, and their amygdalas, which handles emotional memory and the assessment of negative consequences."
According to the report on NBC News, the study was funded by The National Institutes of Health, the Office of National Drug Control Policy, and Northwestern Medicine’s Warren Wright Adolescent Center.
The study, which was published in The Journal of Neuroscience, states, "The present findings suggest that further study of marijuana effects are needed to help inform discussion about the legalization of marijuana."