A new study has shown that the effects of smoking marijuana include brain changes in areas associated with motivation and emotion.
The study is reportedly the first to study even light marijuana use.
“Some of these people only used marijuana to get high once or twice a week,” said co-author Hans Breiter as quoted in Northwestern University’s Science Newsline. “People think a little recreational use shouldn’t cause a problem, if someone is doing OK with work or school. Our data directly says this is not the case.”
The report raises the debate that the effects of smoking marijuana — even casually — may impact long-term health. But the study does not determine if casual to moderate use is harmful to the brain in the long term.
The study analyzed 20 pot smokers and 20 non-pot smokers between 18 and 25. Scientists asked them to estimate how much marijuana they smoked and how often they lit up over a three-month test period. Even those who smoked once a week showed brain abnormalities, while larger changes were seen in those who smoked more.
Studies on the effects of alcohol have shown similar results — noting brain changes that impact mood and emotion.
The study comes out amid changing public perception of the drug, with marijuana legalized in Colorado and parts of Washington state.
A number of other states have introduced — some passing — legislation that decriminalizes the drug, including most recently the state of Maryland.