Are rumination and worry two sides of the same coin? A structural equation modelling approach

Worry and rumination are two types of Repetitive Negative Thinking (RNT) that have been shown to be related to the development and maintenance of emotional problems. Whereas these two forms of RNT have traditionally been regarded as distinct and differentially related to psychopathology, researchers have recently argued that worry and rumination share the same process and show a very similar relationship to different forms of psychopathology. In a series of three studies, we employed a structural equation modelling approach to compare these competing hypotheses. Results showed that a bi-factor model (representing RNT by one latent factor with two uncorrelated method factors) provided a better fit to the data than a two-factor model (with worry and rumination represented by separate factors). In addition, the shared variance within the bi-factor model fully accounted for changes in symptom levels of depression and anxiety in two prospective studies. These findings support a transdiagnostic account of RNT. Implications for theory, measurement and clinical practice are discussed.