There is a developing body of research looking at the opportunity to use. Factors associated with opportunity to use cannabis include using alcohol, using tobacco and the combination of alcohol and tobacco use (Caris et al., 2009; Neumark et al., 2012; Wagner and Anthony, 2002). In Chile and the US, males have been found to be slightly more likely than females to have a chance to use cannabis (Caris et al., 2009; Van Etten and Anthony, 1999), but these gender differences have not been consistently observed (Wells et al., 2011). Childhood religious practices are associated with decreased likelihood of cannabis use opportunity (Chen et al., 2004), and those with externalising behaviour problems have been found to be more likely to have a cannabis use opportunity (Neumark et al., 2012; Reboussin et al., 2015). Perhaps unsurprisingly given that first cannabis use opportunity typically occurs in late childhood or early adolescence, lower parental involvement and higher levels of coercive discipline have been found to be associated with increased likelihood of cannabis use opportunity (Chen et al., 2005). The effect of parenting continues
