This paper reviews school-based (n = 212) and clinically-based (n = 68) positive psychological interventions (PPIs) for children and adolescents. A new 3 × 3 classification of PPIs was developed
based on the processes and content of the PPI and the outcomes measured. This classification involves 9 different types of interventions depending on whether the intervention focuses on
positive, remedial, or both positive and remedial processes and content, and whether the intervention aims to evade or address challenges, deficits, or disorders or improve or elicit positive
outcomes. Positive content-balanced outcomes interventions were the most common type used in schools (38%) and clinical settings (63%). Mindfulness was the most common approach used (49%
in schools and 71% in clinical settings). Surprisingly, relatively few studies focused on well established positive psychological constructs, such as strengths, hope, and gratitude. Overall, the
results suggest strong support for the use of PPIs in school and clinical contexts.