the participants’ anticipation and response to the targets were dulled in the nucleus accumbens — a pleasure center of the brain. Researchers claimed this made them at risk of later addiction to marijuana or other drugs.
While the research team didn’t examine the volunteers’ feedback toward marijuana-related cues, past research showed that the brains of people who habitually use mild psychedelic drugs responded strongly to signs related to their drug of choice.
A separate study by senior author Mary Heitzig, Ph.D., a professor at the University of Michigan, found that marijuana use causes complications with emotions and the brain’s ability to focus, leading to structural brain changes.
While studying adolescent marijuana use and how it affects emotions, Heitzig examined neural responses to emotional words in heavy marijuana users. Compared with non-users, adolescent smokers had less activity in emotional processing while reading negative words. In heavy users, activity in the amygdala (a region responsible for emotions) was lower for both negative and positive words.
Trucco and her colleagues plan to conduct a 10-year longitudinal study involving 10,000 adolescent marijuana users nationwide. They are hoping to pinpoint the age of vulnerability, the potency of marijuana use, and how the level of use impacts the brain via fMRI scans
