Evaluating the empirical evidence for three transdiagnostic mechanisms in anxiety and mood disorders.

High co-morbidity among mental disorders indicates that common transdiagnostic mechanisms underlie various psychopathology, yet there has been little research effort to empirically explicate transdiagnostic processes. A few existing studies are limited in the number of transdiagnostic mechanisms and mental disorder categories explored. The current study addresses these limitations by examining the relationship between three transdiagnostic processes (experiential avoidance, rumination, and emotion dysregulation) and symptom severity of five mental disorders (generalized anxiety disorder, panic disorder, social anxiety disorder, specific phobia, and depression) in a college sample (N = 266). Applying Structural Equation Modeling (SEM), three transdiagnostic models were evaluated, with the five latent variables of mental disorder regressed onto each transdiagnostic process. The results showed that all transdiagnostic models-except the emotion dysregulation model-generally fit the data well. Among the tested models, the strongest evidence was found for experiential avoidance as a transdiagnostic mechanism underlying multiple disorders, suggesting the need for further research effort to reduce experiential avoidance in diverse clinical populations.