This story reports on a study of 2688 high school students in 10 public high schools across LA. These kids answered questions about smoking, vaping, and pot use as 9th graders and then again as 11th graders. The bottom line: a 9th grader who had used e-cigs (Juuling wasn't a thing then, but think cousin-of-Juul) or hookah was three times more likely to use marijuana in some form as an 11th grader. There are lots of possible reasons why, ranging from social stratification around risk taking behavior to addiction. Almost regardless of the why, it's important to know these numbers and to share them with your kids. Talk about this stuff. Don't put your head in the sand and think it's not happening at your school or even under your roof. If it is, opening the lines of communication is the best first step.