This is a follow-up to the 2007 review of the literature on online / offline interventions done by Marks, Cavanagh, & Gega (Psychology Press). Consequently, this review includes summaries of research published since 2006 to date. Since publication of that original work, the number of references about online / offline interventions has mushroomed greatly, to the point that many more chapters were added to cover as many references as possible. None are included in the previous literature review. This book covers research summaries with separate chapters ranging from internalisations (anxiety, depression) to addictions, externalisations, and children and their families, physical illnesses, severe mental illnesses, including obsessive compulsive disorders, with one entire chapter dedicated to where most of the research has occurred in the last decade, and that is -- Post-traumatic Stress Disorders. A whole section is dedicated to separate chapters on Counselling, Psychotherapy, and Training. A final chapter covers many controversial issues in online / offline interventions, including cost-effectiveness, extra-channel non-verbal behaviour, the place of theory in online/offline interventions, and the now-predictably positive future of online interventions as the major approach to deal with most mental illnesses in the 21st century.