The challenges of studying marijuana’s effects on the heart and brain

Over the past decade, marijuana use, both recreational and medicinal, has grown as state governments across the U.S. have legalized its use. But while it might be legal for adults to light up, the question of whether it is harmful or helpful in many cases remains unanswered.
Over the past decade, marijuana use, both recreational and medicinal, has grown as state governments across the U.S. have legalized its use. But while it might be legal for adults to light up, the question of whether it is harmful or helpful in many cases remains unanswered.