本研究共分为三个部分。首先，本研究考察了儿童创伤后应激反应随时间变化的趋势。第一部分研究通过追踪设计，对芦山县某校学生进行追踪调查，在芦LlJ地震后2周收集了333份数据测量了急性应激障碍(acute stress disorder, ASD ),随后地震后1._5个月，6个月，12个月，24个月和48个月分别收集了331份，272份，306份，2_53份和190份测量儿童创伤后应激障碍(posttraumatic stress disorder, PTSD)症状的数据。第一部分旨在探讨ASD和PTSD症状的检出率和得分随时间的变化趋势，以及PTSD症状与时间的函数关系。结果发现:震后2周ASD症状的检出率为30.0070, 1.5个月，6个月，12个月，24个月和48个月时PTSD症状的检出率分别为8.1 070 , 6.3 070 , 6.1 070 , 4.4%和4.7 070;即随时间呈现一定的下降趋势，其中ASD到PTSD症状检出率的下降最快，2年后PTSD症状检出率几乎不变;PTSD症状与时间呈对数函数关系(y=-1.25534 In x +19.38737，且在4个月以前PTSD症状下降速率最快，4个月以后PTSD症状下降速率减缓。
Nature disasters occurred frequently in China. Posttraumatic stress symptoms are widespread among the individuals experienced nature disasters. But not all of them would be onset of posttraumatic stress disorder (PTSD). In addition, the resource of psychological treatment is limited after nature disaster and the work of psychological assistance post-disaster is still on development in our country. Therefore, to identify the high-risk groups and understand the features of posttraumatic stress symptoms development among people after nature disaster are important. This study took children survived from the Lushan earthquake as subjects to explore the trajectories, the phase features and the risk and protective factors of children posttraumatic stress symptoms.
This study consists of three parts. Study 1 aims at exploring the tendency of posttraumatic stress symptoms among children over time. The longitudinal study was used. The students from a school located Lushan county were accessed at 2 weeks after the earthquake by the Acute Stress Disorder Scale(ASDS), followed at 1.5, 6, 12,24 and 48 months after the earthquake by the University of California at Los Angeles PTSD Reaction Index for DSM-IV (UCLA PTSD-RI). Finally, 333, 331，272, 306, 253 and 190 students completed the questionnaire at 2 weeks, 1.5, 6, 12, 24 and 48 months, respectively. The results showed that the prevalence of ASD symptoms was 30.0070, the prevalence of PTSD symptoms at 1._5, 6, 12, 24 and 48 months respectively was 8.1%，6.3 070, 6.1%，4.4070 and 4.7070. The relationship between PTSD symptoms and time present as a logarithmic function (y=一1.25534 In x+19.3 8737).Though the logarithmic function, the decline speed of PTSD symptoms was the most fast before 4 months after the earthquake.
Study 2 aims at investigating the trajectories of posttraumatic stress symptoms among children and the risk and protective factors. The latent class growth analysis was used to analyze the data from 304 students who completed the UCLA PTSD-RI at least twice. The results showed 4 trajectories of PTSD symptoms, namely resilience (53.8070), low symptoms (32.6070), recovery (7.0070), high symptoms (6.6070). We also found that double left-behind before the earthquake, bad relationship with mother, injured during the earthquake, and the detection of ASD at 2 weeks were the risk factors of high symptoms, recovery or low symptoms for children.
Study 3 aims at exploring the phase and features of children PTSD symptoms. In total, 22 students from the original subjects were in-depth interviewed at 48 months after the earthquake. Four phases of posttraumatic stress symptoms among children were identified. The first stage was in lweek after the earthquake, and children were experiencing highly acute stress response. The second stage was from 1 week to 1 month after the earthquake, and posttraumatic stress symptoms sharply decrease among children. The third stage was from 1 month to 2 years, PTSD symptoms remit little by little. But in the third stage, children were vulnerable by other stress events.
The fourth stage was 2 years after the earthquake, children almost were not affected by the earthquake and they rarely thought of the earthquake. Close person death and trauma exposure was the risk factors and good social support was the most important protective factors of PTSD symptoms among children.
In conclusion, the main findings of this study as follows.
(1)Four stages of posttraumatic stress were found by qualitative analysis. However, 4 months was a time point of the decrease speed of PTSD symptoms by quantitive analysis and 4 months exactly divided the third stage into two stages, including 1 month to 4 months and 4 months to 2 years. Finally, the time line of posttraumatic stress symptoms among children was divided into _5 stages and was named as acute stress stage (1 week), generally stable stage (1 week}l month), quick recovery stage (1 month}4 months), slow recovery stage (4 months}2 years) and new life stage (2 years).
(2) Four trajectories of PTSD symptoms among children were found, resilience (53.8070), low symptoms (32.6070), recovery (7.0070) and high symptoms (6.6070). By qualitive analysis, the results showed that at the aspect of time line, resilience group recover sooner than some of low symptoms group and high symptoms group.
(3) Trauma exposure had directly affects on the acute stress reaction but did not predicted the trajectories of PTSD symptoms among children. Good social supports predicted resilience trajectory of PTSD symptoms among children. Good social supports include not double left-behind children, escaped with parents during the earthquake, the peer support and the non-governmental organizations (NGOs) and the government support. Especially lack of emotional support from parents was the risk of PTSD symptoms among double left-behind children.
In conclusion, this study has important implications in practice and theory. In the practice, first, the results about trajectories and stages of children's PTSD symptoms suggested that the project of children psychological treatment post-disaster should last at least 2 years or until the post-disaster reconstruction completed; second, the children with high trauma exposure and low social support were high risk of continuous high PTSD symptoms which need the psychological treatment most; third,social network reconstruction may be good means to treatment. In the theory, the study first revealed the logarithmic function relationship between PTSD symptoms and time; this study first put forward five stages of children PTSD symptoms which enriched the theory of PTSD; the qualitative analysis revealed the mechanism of the influence factors; the study also provided a development psychology perspective to understand children posttraumatic stress reaction.