Randomised or quasi-experimental studies of interventions to reduce symptoms of PTSD that resulted from either a single event (Type I) or from multiple exposure (Type II) in a school setting with at least one "no-intervention" or alternative intervention control group were eligible for inclusion. Studies were also included if standardised instruments were used to evaluate PTSD symptoms. Studies were excluded if treatment was for complex Type II trauma reactions from sexual or physical abuse or ongoing maltreatment, or if sufficient data to make calculations were not provided.
The studies were conducted in the United States, Armenia, Indonesia, Israel, Sri Lanka, Israel, United Kingdom, Bosnia, Lebanon and Kosovo and the trauma types students were exposed to were war or political conflict, exposures to natural disasters including earthquakes, hurricanes and tsunami, community violence and terrorism. Student age ranged from seven years to 19 years. The main treatment approaches used in the interventions were cognitive behavioural therapy, Play/Art, Eye Movement Desensitization and Reprocessing and Mind-Body Skills, although multiple forms of treatment were utilised in several studies. The interventions were delivered by therapists, social workers, teachers, school counsellors, clinical psychology trainees and mental health professionals. The control treatments included wait-list controls, clinic-based intervention, no intervention, individual intervention and partial interventions.
The authors did not state how many reviewers performed the study selection.