E-cigarettes an evidence update A report commissioned by Public Health England

19821984198619881990199219931994199619981999200020012002200320042005200620072008200920102011201220132014Smoking Prevalance (%)E-cigarettes: an evidence updateFigure 8: Prevalence of regular smoking among 11–15 year olds in England 1980–2014 214121086420Please note: decimal places were not used in the published data.GatewayThe gateway theory or hypothesis is commonly invoked in addiction discourse, broadlyto suggest that the use of one drug (sometimes a legal one such as tobacco or alcohol)leads to the use of another drug (sometimes an illegal one) but its definition iscontested. No clear provenance exists and its origin appears to derive from lay,academic and political models [22]. It is apparent that discussions about the naturalprogression of drug use observed in longitudinal studies of young people appear tohave morphed into implicit conclusions on causality without any evidential backing.Some have argued that the effect could be causal if the use of one drug, biochemicallyor pharmacologically, sensitises the brains of users to the rewarding effects of otherdrugs [23] making the dependent use of these other drugs more likely. However, thereare many plausible competing hypotheses for such a progression [24] including i)shared networks and opportunities to purchase the drugs; and ii) individualcharacteristics such as genetic predispositions or shared problematic environment.Academic experts have stated that the gateway concept “has been one of the mostcontroversial hypotheses…in part because proponents and opponents of the hypothesishave not always been clear about what the hypothesis means and what policies itentails” [24]. Indeed, a recent analysis of gateway concluded “Although the concept of2 Smoking drinking and drug use among young people in England surveys. Health and Social Care Information Centre, 2014.37