Not sure about cnn, but the effects these studies "discovered" are well known, they could just ask long time users. A regular advice is to stop smoking two week

Not sure about cnn, but the effects these studies "discovered" are well known, they could just ask long time users. A regular advice is to stop smoking two weeks before taking a test, because fats accumulate thc. Also, there is a day (rarely two) of light aftereffects after smoking it. Daily smoking leads to having these all the time, which may help your mood, but reduce your cognitive sharpness as well, similar to afternoon satiety. But frankly I'd better focus on reasons why they turn to smoking and drinking rather than to other activities. You can't stop drug use by just saying "drugs bad mkay, alcohol bad".