Prior treatment of SUDs markedly increased the likelihood of treatment following onset of new SUDs. Familiarity with the treatment system may contribute to treatment seeking when new SUDs arise. By serving as a marker of severity, comorbid SUDs may also increase the likelihood of treatment-seeking (Chiappetta et al., 2014; Compton et al., 2007; Garcia-Rodriguez et al., 2013; Hasin et al., 2007; Rubio et al., 2014, 2013).
