Subtypes of substance dependence and abuse: implications for diagnostic classification and empirical research

Aims:To evaluate the relevance of a form of diagnostic classification called clinical subtyping in relation to possible revisions in the diagnostic criteria for substance abuse and dependence in psychiatric classification systems.

Methods:A general rationale for subtyping is presented. To explore the implications for diagnostic classification, recent research on a variety of subtyping schemes is reviewed in terms of the development of new subtypes and the validation of established theories.

Results:Subtypes of alcoholism and other psychiatric disorders have been proposed since the beginning of modern psychiatry. Recent subtyping research suggests that no consensus has emerged about the nature, much less the number, of subtypes that could be used to characterize the clinical heterogeneity assumed to be present in groups of people with substance use disorders. Although several relatively simple binary typologies have been developed (e.g. Cloninger's type I and type II; Babor et al.'s type A and type B), validation research has produced mixed results in terms of the construct, concurrent and predictive validity of these classifications.

Conclusions:The adoption of a subtyping scheme in the major psychiatric classification systems is not recommended until further international research is conducted.