The main objective of this longitudinal research is to answer the following question: What is the relationship between tobacco and cannabis use trajectories from adolescence to young adulthood?
And more specifically we are interested in:
A. If the use of one of the substances (tobacco or cannabis) decreases overtime, does the use of the other one increase to compensate? Are other substances (such as alcohol, for example) also used to compensate in these cases?
B. Does the probability to become a tobacco smoker increase when cannabis use is heavier or has lasted longer?
C. What are the risk and protective factors that can predict that the use of tobac...