The relevance of reinforcement sensitivity theory to social anxiety and response to cognitive behavioural therapy for social anxiety disorder

The overall aim of this thesis was to investigate the relevance of Reinforcement Sensitivity Theory (RST) to social anxiety (SA) in the community and response to cognitive behavioural therapy (CBT) outcome for social anxiety disorder (SAD). Three studies were conducted to realise this objective. Study 1 investigated the relationships between RST traits (and similar personality variables) and observation anxiety (OA) and interaction anxiety (IA). Participants in the community (N=200; Age M=26.84) completed questionnaires. The original Behavioural Inhibition System (o-BIS), revised BIS (r-BIS), Fight-Flight-Freeze System (FFFS), Sensitivity to Punishment (SP; a measure of BIS), neuroticism, negative affectivity (NA), and a composite score of all of these personality variables, were all positive predictors of OA. Fun-Seeking (Fun-S), positive affectivity (PA) and extraversion were negative predictors. For IA, the same pattern of results was found except that FFFS was not a significant predictor. Study 2 used an experimental mood-induction procedure to investigate the effects of RST traits on cognitive, affective and avoidance responses to induced SA with a community sample (N = 103; Age M=30.22). For affective responses, SP positively and independently predicted post-induction fear and SP interacted with Sensitivity to Reward (SR; a measure of BAS) to predict post-induction anxiety. For cognitive responses, SP positively predicted cognitions I want to leave/exit/escape this situation and People can see that I feel anxious. I am being judged/evaluated negatively by these people was positively predicted by FFFS and Fun-S, and negatively predicted by Drive. For avoidance responses, SP positively predicted desire to avoid but active avoidance was not significantly predicted by any RST trait. Study 3 investigated how RST traits influenced responses to CBT outcome for SAD. Sixteen participants (Age M=41.82) attended treatment and completed various pre- and post-treatment outcome measures. For IA: r-BIS, o-BIS and SR each moderated relationships between pre- and post-treatment IA, with high personality scores being associated with higher post-treatment IA. For OA: Reward-Responsiveness (RR), Drive, and SR each moderated the relationship between pre- and post-treatment OA with high personality scores resulting in higher post-treatment OA. For the Cognitive Checklist Anxiety (CCL Anx; general anxiety cognitions); Drive and FFFS each moderated the relationship between pre- and post-treatment CCL Anx with low personality scores being associated with higher post-treatment CCL Anx. Overall, results suggest that RST traits and SA share dimensional relationships; that RST traits affect cognitive, affective and avoidance responses to SA; and that high BIS and BAS scores relate to higher post-CBT outcome scores for SAD.