The decision to combine diagnostic criteria for alcohol abuse and dependence was based on studies showing that all of the criteria lay along a latent alcohol use severity continuum (Shmulewitz et al. 2010; Mewton et al., 2010; Hagman and Cohn, 2011). Similar findings have been reported for cannabis, cocaine, heroin, amphetamine and prescription drug use disorders (Saha et al., 2012; Hasin et al., 2012).
