Most studies on marijuana use have looked at long-term heavy marijuana users and show brain changes.
Jodi Gilman, PhD, from the Department of Psychiatry, Massachusetts General Hospital, Boston, says “Our study is different in that it looks at young adult recreational users who are not addicted based on a psychological interview and we found observable brain changes in this group. This is concerning, given that there are roughly 18.5 million recreational users of marijuana”.
Nucleus Accumbens – Brains Reward & Pleasure Sensor
This new study, Dr. Smith said, “appears to demonstrate that increasing amounts of cannabis used recreationally are associated with increasing severity in brain abnormalities. Their findings are also consistent with my recent work in young adults who were daily cannabis users as teens, as both studies observed abnormalities in the nucleus accumbens,” Dr. Smith said.
The nucleus accumbens is the area of the brain responsible for experiencing reward and is largely considered the pleasure center of the brain. It is interesting that these abnormalities exist given the low levels of cannabis consumed. These findings will be quite concerning if they are present after an extended period of abstinence.
“These abnormal structural changes in the amygdala and nucleus accumbens could indicate that the experience with marijuana alters brain organization and may produce changes in function and behavior,” study investigator Anne Blood, PhD, from the Department of Psychiatry, Massachusetts General Hospital, added in a statement. “It also is possible that the brain is adapting to marijuana exposure and that these new connections may encourage further marijuana use.
Young Adult Use Concern for Legalization of Marijuana
The ongoing studies of the affects marijuana has on the brain have increased concern associated with its use among the young adult population. If marijuana use alters the brain structure in such a significant way with only occasional use, what are the implications for those who engage in regular long term use of the drug?
“Our findings, which need to be followed up with longer-term studies, raise serious concerns about efforts to legalize recreational marijuana use, particularly for young adults,” said study investigator Hans C. Breiter, MD, professor of psychiatry and behavioral science at Northwestern University Feinberg School of Medicine, Chicago, Illinois.