Psychology Theses

The increasing burden on behavioural healthcare services and major unmet need for care necessitate the development and evaluation of innovative resources to target prevalent, burdensome and costly behavioural health problems. Contextual CBT provides a conceptual framework that is ripe for innovative scientific inquiry and encompasses therapeutic approaches with the scope intervene for a range of topographically dissimilar but functionally similar outcomes. The programme of research reported in this thesis focused on developing and evaluating innovative resources to extend the reach, enhance the effectiveness and advance the evaluation of contextual CBT interventions. Study 1 focused on the first overarching aim of this programme of research: evaluating the evidence base for novel eHealth treatments that have the potential to extend the reach of contextual CBTs. A systematic review and meta-analysis was conducted to determine the efficacy and acceptability of contextual CBT eHealth treatments as stand-alone interventions for improving common mental health outcomes. Twenty-one randomised controlled trials were included in the review. Findings revealed that the treatments were acceptable and efficacious in improving common mental health outcomes including anxiety, depression, and quality of life, but not more so than comparison interventions. Study 2 focused on the second overarching aim of this programme of research: developing and evaluating an innovative blended intervention with the potential to enhance the effectiveness of contextual CBT. This study built upon its predecessor by investigating the efficacy of a treatment that combined eHealth and traditional face-to-face contextual CBT for the most common substance use problem: smoking. One hundred fifty adults smoking 10 or more cigarettes per day were randomly assigned to six weekly group sessions of behavioural support, ACT, or ACT combined with the smartphone application. Findings revealed that the blended intervention was acceptable to participants and efficacious in promoting smoking reduction, acceptance, and present-moment awareness at post-treatment. Smoking cessation outcomes, however, were comparable to the comparison interventions. Study 3 focused on the final overarching aim of this programme of research: developing and evaluating an innovative resource that holds promise in advancing the evaluation of contextual CBT interventions. This study investigated the preliminary psychometric properties of a novel measure of a primary target of the contextual CBT interventions evaluated in Studies 1 and 2: valued living. A separate sample of 150 adults participated in this psychometric evaluation of the Values Wheel. Findings provided preliminary support for the psychometric properties of the Values Wheel as an idiographic and weighted measure of valued living. The three studies reported in this thesis were published in peer-reviewed academic journals. The publications have made original contributions to the scientific knowledge, substantiated and supported existing literature, and given rise to active research in the field. The publications also have several implications for contextual CBT practitioners. Limitations and directions for future research are discussed.