Like in Musci et al (2016a), wherein the focus was on age of first tobacco use, we found evidence of enhanced effects of our Classroom-Centered intervention on age of 1st use of marijuana for those individuals at the upper end Uhl el al. (2010)’s smoking quit success score. The higher the score, the greater the delay in age of first use of marijuana. The significance of this enhanced effect is highlighted by the literature suggesting that the earlier the age of first use of most substances, the greater likelihood of escalating and prolonged use over development.
