This seems like a no-brainer but a new study finds students who smoke pot don’t do as well as those who don’t.

Web MD reports.

Smoke Weed in College and Your Grades May Go to Pot

College students who smoke marijuana appear more likely than their peers to skip classes — which eventually leads to poorer grades and later graduation, a recent study suggests.

The study, which followed more than 1,100 college students for eight years, found that those who smoked pot tended to skip more classes. The more frequent their marijuana use, the more often they missed class.

Those skipped classes, in turn, were linked to a lower grade point average and delayed graduation.

The findings, published in the journal Psychology of Addictive Behaviors, do not prove that marijuana use was the root cause of students’ academic struggles.

But lead researcher Amelia Arria said her team accounted for a range of other factors, including students’ drinking and other drug use; involvement in sports and other extracurricular activities, and psychological factors such as depression.

They also measured some personality traits, like the tendency to act impulsively to seek “sensation,” said Arria, an associate professor of behavioral and community health at the University of Maryland School of Public Health.

“We think that skipping-class variable is an important finding,” Arria said.