New clinical strategies of assessment of comorbidity associated with substance use disorders.

The introduction of "dual diagnosis" had the merit of drawing attention on substance use among patients with mental illness. In due course, as what often happens with innovations, the concept of dual diagnosis displayed considerable limitations and was progressively replaced by comorbidity. This paper critically reviews the limitations of dual diagnosis and comorbidity and formulates an alternative proposal based on clinimetric methods. In many instances of diagnostic reasoning in psychiatry and in clinical psychology, the process ends with the identification of the disorders and their diagnoses. However, diagnostic end-points, the customary guidance of diagnostic reasoning, should be replaced by the conceptualization of disorders as "transfer stations," which are amenable to longitudinal verification and modification. Indeed, diagnoses might encompass a wide range of manifestations, seriousness, prognosis, and response to treatment that need to be evaluated. A new clinimetric approach which takes advantage of clinimetric methods (including macro-analysis, micro-analysis, staging, and evaluation of subclinical symptoms) is proposed. This approach may allow an accurate analysis of the different problem areas of each patient and their hierarchical organization and may yield important implications for mental health and substance abuse clinics.