Swipe left or right to scroll. Monitoring the Future Study: Trends in Prevalence of K2/Spice (Synthetic Marijuana) for 8th Graders, 10th Graders, and 12th Graders; 2018 (in percent)* Drug Time Period 8th Graders 10th Graders 12th Graders K2/Spice (Synthetic Marijuana) Past Year 1.60 2.90 3.50 February 11, 2020
