This book summarizes how awareness of one's emotions, emotion regulation, emotion appraisal, emotionally laden memories, and emotional competencies influence mental health. Each component is discussed with regard to mechanisms, development, and their impact on psychotherapy. The first part of the book discusses theories linking emotional processes, psychopathology, and mental health. The second part of the book discusses the developmental pathways of change in emotional processes over the lifespan. The third part of the book discusses pathways of change in emotional processes during psychotherapy and includes different forms of treatment of psychological disorders.