Investigating whether Intolerance of Uncertainty is specifically associated with threat extinction over diagnostic measures of anxiety-related conditions

Modern exposure-based therapies operate on principles of threat conditioning and extinction. Previous research has demonstrated that trait-level intolerance of uncertainty (IU) is specifically associated with worsened extinction learning whilst controlling for trait anxiety. Hence, IU may serve as a useful focus for researchers aiming to improve the effectiveness of exposure-based therapies. Yet, little is known as to whether IU is associated with extinction learning whilst controlling for disorder-specific symptom measures. A two-day Pavlovian conditioning task was carried out, consisting of threat acquisition, extinction, and extinction retention phases. An opportunity sample (N=101) completed IU, trait anxiety, and various disorder-specific symptom questionnaires e.g., generalised anxiety disorder. before engaging in the conditioning procedure. Skin conductance magnitudes, and behavioural ratings of anxiety and stimulus expectancy were used as indices of conditioned responding, and extinction by extension. Analyses revealed that successful threat conditioning was observed for all three measures during threat acquisition, yet extinction was not observed during both the extinction and retention phases. IU was not specifically associated with individual differences in extinction as indexed by differential SCR magnitudes, contradicting prior research. Further, IU was specifically associated with differential stimulus expectancy and anxiety ratings within extinction and retention respectively, whilst controlling for symptom measures. Lastly, IU was not associated with any other extinction measure. Exploratory examinations of traits and symptom measures revealed a lack of associations with CS+/CS- difference scores, whilst correlating with overall arousal and individually to conditioned stimuli. Interpretations, limitations, and future research are discussed in relation to IU and extinction learning.