This volume brings together basic research on the nature of stress reactivity with up-to-date research on the effectiveness and mechanisms of mindfulness interventions. The chapters review the major research areas that elucidate the impact of stress reactivity on health, and explore the mechanisms and effectiveness of mindfulness-based approaches for stress reduction and improved physical and emotional health. The first section examines biopsychosocial mechanisms of stress reactivity such as allostasis and allostatic load, neurobiology of stress, biology of the “fight-or-flight” and “tend-and-befriend” responses, and psychoneuroimmunology. This section concludes by addressing the roles of perception and appraisal, including the role of perceived threat in stress reactivity as well as the role that negative perceptions of the stress response itself play in compromising health. The second section opens with review of leading psychological models of mindfulness, including self-regulation, reperceiving, and the Intention, Attention, Attitude (IAA) triaxiomatic model. Subsequent chapters discuss mindfulness-based interventions and mechanisms of change for stress and related clinical conditions including chronic pain, traumatic stress, anxiety and related disorders, and clinical depression. The final chapter reviews possible neural networks and brain mechanisms associated with mindfulness meditation practice. As the research on stress reactivity and mindfulness-based stress reduction continues to proliferate, this book offers readers a single volume covering the most relevant information across this vast terrain. Other available volumes offer in-depth coverage of stress research with little mention of mindfulness and stress reduction. Conversely, many texts on the topic of mindfulness and mindfulness-based interventions do not adequately cover the biopsychosocial processes of stress reactivity.