al., 2009), some mental health factors (Behrendt et al., 2011) and gender (Ridenour et al., 2006; Wittchen et al., 2008). Exploring speed of transition to cannabis opportunity will determine whether risk factors for dependence are already exerting influence on drug use behaviours at the start of an individual’s cannabis involvement, which has utility for improving understanding of how dependence develops (Hines et al., 2015a). Applying survival analysis methodology to this area allows for quantification of time to cannabis use opportunity and from opportunity to dependence, and identification of what factors may impact upon the speed of these transitions.
