Abstract
There is mounting evidence to suggest that people with anxiety disorders exhibit a risk-avoidant decision-making bias, the safety bias, believed to be implicated in the development and maintenance of anxiety pathology. This thesis sought to empirically investigate the hypothesised relationship between risk-avoidance and pathological anxiety in several clinical and non-clinical samples, using self-report and behavioural indices of risk-taking. Furthermore, this thesis examined the clinical implications of risk-avoidance for treatment-seeking and as a cognitive-behavioural therapy (CBT) treatment outcome variable. Study 1 investigated the association between risk-avoidance, social anxiety, and behavioural inhibition sensitivity (BIS) in an undergraduate sample. Results suggested that risk-avoidance may be a partial mediator of the relationship between BIS and social anxiety. Studies 2 and 3 investigated whether risk-avoidant preferences generalised to clinical online and treatment-seeking samples. Anxious individuals reported reduced risk propensity relative to non-clinical control participants (Study 2). Furthermore, aspects of risk-avoidance were shown to contribute uniquely to anxiety disorder symptoms, even when controlling for a robust dispositional vulnerability, neuroticism (Study 3). Study 4 examined the relationship between risk-aversion and treatment-seeking preferences in an online sample of anxious individuals. Individuals with SP and GAD (but not OCD) reported greater risk-aversion when compared to non-clinical control participants. Furthermore, willingness to seek treatment was found to be positively associated with aspects of risk-avoidance. Finally, studies 5 and 6 further explored self-reported domain-specific risk-taking as a treatment outcome in an internet-delivered CBT (iCBT) program for GAD and group CBT (CBGT) treatment for SP and PDAg. Patients in all treatment groups showed significantly decreased tendencies towards risk-avoidance in the social and recreational domains. In Study 5, mediation analyses revealed risk-taking to be a significant mediator for treatment outcome for depressive symptomatology (but not GAD symptomatology). In Study 6, results suggested that reductions in risk-avoidance were significantly associated with improvements in SP, PDAg and depressive symptoms. Together, the findings of this program of research support the existence of a risk-avoidant decision-making bias in those with pathological anxiety, and further provides evidence for the theoretical and clinical implications of risk-avoidance in the development, maintenance and treatment of anxiety disorders.