Posttraumatic stress disorder (PTSD) in children and adolescents occurs as a result of a child’s exposure to one or more traumatic events: actual or threatened death, serious injury, or sexual violence. The victim may experience the event, witness it, learn about it from close family members or friends, or experience repeated or extreme exposure to aversive details of the event. Potentially traumatic events include physical or sexual assaults, natural disasters, and accidents.