The role of individual differences in social anxiety on threat extinction and avoidance

Social anxiety disorder is a prevalent and debilitating disorder that significantly impairs quality of life. Although Cognitive Behavioural Therapy, that incorporates exposure as a primary component, is the first-line treatment for social anxiety disorder, relapse after treatment is common. Principles of threat extinction serve as a laboratory-based model for exposure therapy. Despite this, relatively few studies have investigated the effect of social anxiety on extinction learning processes. Therefore, the primary aim of this work was to examine the relationship between individual differences in social anxiety and learning processes within Pavlovian threat extinction paradigms. Paper 1 used two separate socially relevant threat extinction experiments to assess the relationship between social anxiety and threat extinction and retention. In Paper 2, a systematic review of the literature that has investigated the association between social anxiety and threat conditioning and extinction was conducted. The findings from Paper 1 and Paper 2 did not provide evidence that social anxiety is related to compromised extinction learning or retention. Instead, this work suggests that other maladaptive processes related to social anxiety may account for the maintenance or return of fear after exposure therapy. Thus, Paper 3 examined the effect of individual differences in social anxiety on low-cost avoidance conditioning and extinction and found that social anxiety was associated with increased avoidance behaviour to threat and safety cues after extinction learning. Taken together, the findings suggest that maladaptive extinction of avoidance behaviour, and not extinction learning, is implicated in the maintenance or return of social anxiety related symptoms after exposure therapy. The work of this thesis points towards several suggestions for future clinical research to inform potential targets for exposure-based treatments for social anxiety disorder