Mindfulness and compassion: measurement and mechanisms of interventions

In recent years, there has been an exponential increase in research exploring contemplative constructs, namely mindfulness and compassion, and their potential to enhance psychological functioning. A large body of evidence supports the effectiveness of mindfulness-based interventions (MBIs) for improving mental health and wellbeing, and emerging evidence indicates benefits associated with cultivating compassion. However, significant gaps remain, which impede progress in mindfulness and compassion research. Understanding and empirical testing of the mechanisms underlying the effects of MBIs are limited. Research on MBIs also requires valid and reliable mindfulness measures and existing self-report scales need additional psychometric testing. Despite increasing research attention on self- and othercompassion, there is a lack of definitional clarity and psychometrically robust measures of these constructs. This thesis aims to address these omissions. Following an overview of mindfulness and compassion theory and research, Chapter 2 presents a systematic review and meta-analysis of studies which formally tested mechanisms of MBIs. Chapter 3 examines the specific effects and mechanisms of learning mindfulness, by comparing an online self-help MBI with a matched control condition. Much of effectiveness and mechanism research involves comparing mindfulness scores before and after MBIs, yet the factor structure of commonly used self-report measures before and after MBIs has not been tested; this is addressed in Chapter 4. Chapters 5, 6, and 7 focus on increasing clarity in defining and measuring compassion. Chapter 5 proposes a five-element definition of compassion and includes a systematic review and evaluation of existing compassion measures. Chapter 6 empirically tests the factor structure of the five-element definition using self-report items. Following theoretical and empirical support for the five-element conceptualisation, Chapter 7 uses this definition to develop and validate new self-report measures of self- and other-compassion. Chapter 8 presents a general discussion of the research undertaken, including strengths and limitations, future directions, and implications.