"I need my blanket when I'm scared": the nature and use of safety behaviours in children and adolescents

Safety behaviours have been found to undermine successful exposure in the treatment of anxiety disorders for both adults and children. Although reliable measures of safety behaviour exist in the adult literature, no such measure has been developed specifically for child and adolescent populations. This thesis aimed to address this gap in the literature through two studies. Study One collected qualitative data from children and adolescents to explore their understanding, conceptualisation, and ability to report on safety behaviour use. This provided the foundation for Study Two, which focused on the development and psychometric evaluation of the Safety Behaviour Inventory for Children and Adolescents (SBICA), a measure of safety behaviours in youth. Three factors were identified from the SBICA, which reflected checking behaviours, behaviours related to image management, and behaviours related to physical protection. The SBICA and its subscales demonstrated strong internal consistency, test-retest reliability, construct validity, and the ability to discriminate between clinical and non-clinical participants. The SBICA was also responsive to the effects of treatment. Given its good psychometric properties, the SBICA will prove valuable for both research and clinical purposes.