Abstract/Summary

Anxiety disorders in children and adolescents are highly prevalent and without treatment, are associated with a range of difficulties and poor outcomes. Cognitive behavioural therapy (CBT) is the first line treatment of child and adolescent anxiety disorders. The critical ingredient of CBT is believed to be exposure; a controlled therapeutic technique whereby a person faces an anxiety-provoking stimulus or situation. While exposure-based treatments are effective, 40-50% of young people do not benefit, and almost half of initial treatment responders relapse after treatment. The major focus of exposure therapy has recently moved away from within and between session fear reduction (habituation), and towards the retrievability of new, non-threatening inhibitory associations. Research with adults has identified several strategies to optimise learning during exposure, however, the current state of evidence concerning exposure optimisation, and questions about how best to design exposures in the treatment of childhood anxiety disorders, is unclear. The aim of the studies in this thesis was to address gaps within the literature and to develop a better understanding of potential optimisation strategies for children and young people. Specifically, the thesis aimed to gain a greater understanding of the current state of empirical evidence concerning the optimisation of exposure therapy for child and adolescent anxiety disorders and to explore the effects of adding different verbalisation strategies to exposure on fear responding for adolescents with public speaking anxiety. A systematic review looking at factors associated with differential outcomes from exposure in children and young people with anxiety symptoms/disorders found a distinct lack of replication within the field. The findings generally failed to support a role of habituation-based fear reduction and there was preliminary evidence that some specific strategies may enhance the effects of exposure, such as dropping safety behaviours, parents and therapists discouraging avoidance, and the use of homework, however, methodological limitations precluded firm conclusions from being drawn. A preclinical, experimental study with public speaking fearful adolescents found that neither affect labelling or positive coping statements enhanced exposure on any measure of anxiety (self-rated anxiety, heart rate, or observer ratings of expressed anxiety) from pre-test to 1-week follow-up as participants delivered a series of speeches in front of a pre-recorded classroom audience. Although exposure with positive coping statements yielded a significantly greater reduction in self-rated anxiety compared to exposure with affect labelling and neutral statements immediately post-exposure, there was no advantage in the longer term. The findings also suggested that extinction learning generalised when participants delivered a speech in a novel context. Again however, there was no advantage of any verbalisation strategy on anxiety measures. Finally, there were improvements in social anxiety symptoms, cognitions and use of safety behaviours across all conditions from pre-test to 1-month and 3-month follow up, suggesting that a recorded audience may be a valuable exposure stimulus in the treatment of social anxiety. However, notable methodological limitations prevent firm conclusions from being made. Taken together, the results highlight that evidence concerning exposure optimisation in children and young people is at a very early stage, and that methodologically robust research will be vital for developing the field and improving exposure outcomes in the treatment of child and adolescent anxiety disorders