IntroductionWe investigated the prevalence rates for probable PTSD and used generalized estimating equations to identify risk factors for probable PTSD in children and adolescents exposed to the Lushan earthquake. MethodsA total of 1623 participants completed 3 assessments, including the Children's Revised Impact of Event Scale, at 2weeks, 3, and 6months after experiencing the Lushan earthquake. Additionally, demographic variables and variables related to everyday functioning were evaluated at 2weeks after the earthquake via a self-constructed questionnaire. ResultsThe percentages of children and adolescents who changed from having no PTSD to probable PTSD and probable PTSD to no PTSD at each time point were approximately 8% and 20% of the sample, respectively. The percentage of participants without PTSD increased from 41.1% at the 2-week to 3-month time point to 54.3% at the 3-month to 6-month time point, and the percentage with persistent probable PTSD decreased from 29.6% to 16.4% at the 2 time points, respectively. Female gender, a sedentary lifestyle, and actively helping others were significant risk factors for probable PTSD, whereas initiating communications with others, actively playing with classmates and friends, and the ability to concentrate on academic studies after resuming class were factors that helped protect against probable PTSD. DiscussionResistance to PTSD and persistent PTSD symptoms were both common occurrences in child and adolescent survivors. Specific variables related to everyday functioning may be risk factors for probable PTSD. These findings have implications for agencies that provide mental health services after an earthquake.