The relationship between ASPD and substance use disorders is entirely consistent with the existence of a spectrum of externalising disorders. This relationship held true for males and was partially supported for females. Work by Krueger and colleagues has placed heroin and other drug dependence in the context of a broader externalising spectrum, albeit closely linked to internalising disorders (Krueger & Markon, 2006; Krueger, Markon, Patrick, Benning, & Kramer, 2007; Krueger, et al., 2005). In the current study, there was an increase in other externalising problems (antisocial behaviour/ASPD, prison time) as the number of dependence diagnoses increased, whereas internalising disorders were less consistently linked to greater substance dependence.
