Cracking the Repetitive Negative Thinking Code: Keys to Understanding Anxiety and Depression

There is significant debate as to whether certain cognitive components of anxiety and depression, specifically worry, post-event processing (PEP), and rumination, are best understood as independent constructs (i.e., disorder-specific) or rather, one transdiagnostic construct, so called repetitive negative thinking (RNT), that predicts symptoms of generalized anxiety, social anxiety, and depression respectively. Additionally, it is poorly understood whether the content of RNT related thoughts, or the process of thinking such thoughts, is relevant to understanding how RNT is associated with psychological symptom severity. The current thesis sought to investigate: 1) whether studying worry, PEP, and rumination as one transdiagnostic predictor of psychological symptoms explains additional variance in symptom severity compared to studying worry, PEP, and rumination as individual predictors of psychological symptoms, and 2), whether the content of RNT related thoughts, or the process of engaging in RNT is associated with greater psychological symptom severity. Results indicated that the transdiagnostic measurement of RNT explained additional variance above and beyond disorder-specific measures when predicting participants' (n = 646) symptom severity. Additionally, both RNT content and process are important factors in understanding how RNT is associated with greater psychological symptom severity. Taking into account the methodological strengths and limitation of the current study, such findings lend support to the transdiagnostic model of RNT, and illustrate how the content and process of RNT are relevant to understanding psychological distress.