Pathway between negative interpretation biases and psychological symptoms : Rumination as a transdiagnostic mediator in a longitudinal study

Abstract

Background Both interpretation biases (IBs) and repetitive negative thinking (RNT) have been hypothesized as etiological factors for depression and paranoia, but the complex interplay between the two in driving psychological symptoms remains unknown. Objective: This study examined the transdiagnostic mediating role of RNT in depression and paranoia. It also examined the bidirectional relationships between IB and psychological symptoms in depression and paranoia. Methods A two-wave longitudinal study of UK was conducted with young adults aged 18 to 30 (N=863). Baseline and a one-month follow-up surveys were distributed through a research platform, Prolific. IBs were assessed by the Ambiguous Scenario Test for Depression (ASTD) and Cognitive Bias Questionnaire for Psychosis (CBQp). RNT was assessed by the Perseverative Thinking Questionnaire (PTQ). Depressive symptoms and paranoid thoughts were assessed by the Inventory of Depression and Anxiety Scale (IDAS) and the Revised Green et al. Paranoid Thoughts Scale (RGPTS). Sociodemographic information was also collected. The interplay among IBs, RNT, and psychological symptoms were analyzed using cross-lagged panel models (CLPM). Results Multivariate CLPMs did not support RNT as a transdiagnostic mechanism, nor did they support RNT as a shared mechanism across depression and paranoia. Bivariate CLPMs found that IB did not predict psychological symptoms in both depression and paranoia over time. However, results showed that RNT might potentially be a full mediator between IB and depression, but not paranoia, over time. Conclusion Longitudinal results of this study did not find a significant transdiagnostic effects of RNT in both depression and paranoia. However, this study revealed that RNT might play an important bridging role between IB and depression. This study also contradicted previous findings that IB played a causal role in the development and course of psychological symptoms. Instead, this study revealed that psychological symptoms might precede IB. Further experimental and clinical trials are needed to examine the effects of RNT intervention and to reconsider the efficacy of bias modification on symptom changes.