A Heuristic for Developing Transdiagnostic Models of Psychopathology: Explaining Multifinality and Divergent Trajectories.

Transdiagnostic models of psychopathology are increasingly prominent because they focus on fundamental processes underlying multiple disorders, help to explain comorbidity among disorders, and may lead to more effective assessment and treatment of disorders. Current transdiagnostic models, however, have difficulty simultaneously explaining the mechanisms by which a transdiagnostic risk factor leads to multiple disorders (i.e., multifinality) and why one individual with a particular transdiagnostic risk factor develops one set of symptoms while another with the same transdiagnostic risk factor develops another set of symptoms (i.e., divergent trajectories). In this article, we propose a heuristic for developing transdiagnostic models that can guide theorists in explicating how a transdiagnostic risk factor results in both multifinality and divergent trajectories. We also (a) describe different levels of transdiagnostic factors and their relative theoretical and clinical usefulness, (b) suggest the types of mechanisms by which factors at 1 level may be related to factors at other levels, and (c) suggest the types of moderating factors that may determine whether a transdiagnostic factor leads to certain specific disorders or symptoms and not others. We illustrate this heuristic using research on rumination, a process for which there is evidence it is a transdiagnostic risk factor.