背景：促进儿童健康成长、保护儿童免于伤害，是全社会的共同责任。然而，仍有大量的儿童暴露在创伤事件中。严重的创伤事件经历会增加个体罹患心理和行为问题的风险，对儿童的健康发展产生长期的不利影响。因此，本研究旨在调查普通儿童群体中的创伤事件和心理健康现状，并揭示创伤后常见不良反应间的关系，比如，创伤后应激障碍（Posttraumatic stress disorder, PTSD）、抑郁症状、自尊及其与学校态度间的关系，为儿童保护政策体系及临床实践干预提供参考。
方法：本研究采用分层整群抽样和目标抽样相结合的方法在我国8省56所中小学中对8473名中小学生进行了问卷调查。测量工具包括创伤事件经历核查表（Trauma History Screen-Youth version）、PTSD症状核查表（the PTSD checklist for DSM-5, PCL-5）、简版儿童抑郁量表（Children Depression Inventory-Short Form, CDI-S）、自尊量表（Self Esteem Scale, SES）和学校态度问卷（School Liking and Avoidance Questionnaire, SLAQ）。
结果：研究一以创伤事件经历核查表和PCL-5为测量工具，对儿童的创伤事件经历以其人口社会学特征分布进行分析，结果显示：
1）在被访儿童中，59.35%（n = 4022）儿童至少经历过一件创伤事件。其中，13.07%（n = 880）儿童经历过3种以上的创伤事件，2.24%（n = 151）儿童经历过5种及以上的创伤事件。发生比例较高的创伤事件有：分离（45.15%），严重事故（17.64%），致命疾病（16.90%）和自然灾难（13.93%）。
2）儿童的创伤经历与性别、年龄、父母外出类型、是否住校存在显著相关，男性、高年龄、父母外出、住校儿童经历各类创伤事件的风险更大。
3）我国普通学龄儿童中PTSD症状的阳性检出率较高，占12.05%。男性 [OR (95%CI): 1.31 (1.09 - 1.58)，P = 0.004]、严重事故 [1.30 (1.07 - 1.59)，P = 0.009]、致命疾病 [1.53 (1.26 - 1.86)，P < 0.001]、自然灾难 [1.35 (1.09 - 1.67)，P = 0.005]、被抢劫 [2.25 (1.50 - 3.37)，P < 0.001]、被性侵[2.73 (1.94 - 3.84)，P < 0.001]、虐待 [2.33 (1.71 - 3.18)，P < 0.001]、暴力事件 [2.44 (1.82 – 3.27)，P < 0.001]七类创伤经历均是患有PTSD症状的危险因素。且创伤类型的数量越多，儿童患有PTSD症状的风险越大。
 
研究二以PCL-5、简版儿童抑郁量表（CDI-S）为测量工具，考察儿童PTSD症状与抑郁症状的共病情况，以及PTSD症状与抑郁症状之间的关系，结果显示：
1）在受访儿童中，抑郁症状的筛查阳性率为16.53%（n = 1004）。PTSD症状与抑郁症状的共病率较高，在患有PTSD症状的儿童中，35.39%（n=241）儿童同时患有抑郁症状。
2）父母双方均外出打工 [1.35 (1.13-1.63)，P = 0.001]，虐待 [1.89 (1.35-2.65)，P < 0.001]，PTSD [2.53 (2.04-3.14)，P < 0.001]是儿童患有抑郁症状的风险因素。
 
研究三以PCL-5和自尊量表（SES） 为测量工具，考察儿童PTSD症状与低自尊的共发情况，以及PTSD症状与低自尊之间的关系，结果显示：
1）在受访儿童中，低自尊的筛查阳性率为13.14%（n = 777）。PTSD症状与低自尊的共同发生率较高，在患有PTSD症状的儿童中，18.71%（n = 122）儿童同时具有低自尊表现。
2）致命疾病 [1.33 (1.07-1.65)，P=0.01]、暴力事件 [1.48 (1.14-1.92)，P =0.04]、PTSD症状 [1.48 (1.14-1.92)，P =0.003]是儿童低自尊的风险因素。
 
研究四以PCL-5和学校态度问卷（SLAQ）为测量工具，考察儿童PTSD症状与学校回避态度的共发情况，以及PTSD症状与学校回避态度之间的关系，结果显示：
1）在受访儿童中，学校回避态度的筛查阳性率为8.30%（n = 502）。PTSD症状与学校回避态度的共同发生率较高，在患有PTSD症状的儿童中，15.77%（n = 108）儿童同时持有学校回避态度。
2）男生 [2.38 (1.88-2.94)，P<0.001]、父母双方均外出打工 [1.59 (1.24-2.03)，P <0.001]、住校 [0.64 (0.52-0.81)，P <0.001]、遭遇性侵 [2.26 (1.39-3.66)，P <0.001]和PTSD症状 [1.76 (1.29-2.38)，P <0.001]可以影响儿童对学校的回避态度。
 
研究五分析了儿童PTSD症状、抑郁症状、低自尊与学校回避态度之间的相互作用关系和中介作用，结果显示：
1）PTSD症状、抑郁、低自尊和学校回避态度之间具有显著相关性，且PTSD症状能够显著正向影响学校回避态度。
2）抑郁和低自尊在PTSD症状与学校回避态度之间起显著的中介作用。具体为：一是抑郁的中介作用；二是低自尊的中介作用；三是抑郁-自尊的链式中介作用。
 
结论：1）普通儿童群体中，创伤事件发生率较高，类型多样；2）经历创伤事件后，PTSD症状、抑郁症状、低自尊和学校回避态度的检出率较高；3）患有PTSD症状的青少年更有可能同时具有抑郁症状、低自尊和学校回避态度；4）抑郁和低自尊在PTSD症状与学校回避态度之间起显著的中介作用。
本研究针对公众对儿童心理创伤认识不足，心理资源匮乏以及缺乏预防监督体系等问题，结合儿童保护的视角，提出以下政策和实践工作建议：（1）加强心理健康的知识普及，缓解公众对儿童心理健康的不合理认知；（2）以循证疗法为指导，开发儿童心理干预指南并创新干预服务递送模式；（3）以政府为主导，构建全社会参与、多部门协调的儿童心理保护屏障。

It is the responsibility of the whole society to promote the healthy growth of children and protect children from harm. However, a large number of children are still exposed to traumatic events. The experience of severely traumatic events will increase the risk of psychological and behavioral problems, and have a long-term adverse impact on the development of children. Therefore, the purpose of this study is to investigate the traumatic events and mental health of children in general, while revealing the relationship between common adverse reactions after trauma, such as posttraumatic stress disorder (PTSD), depressive symptoms, self-esteem and school attitudes, so as to provide reference resources for child protection policy system and clinical practice.
A survey by questionnaire was conducted among 8473 students in 56 primary and secondary schools in 8 provinces of China. The tools of survey consisted of Trauma History Screen-Youth version, the PTSD checklist for DSM-5 (PCL-5), Children Depression Inventory-Short Form (CDI-S), Self Esteem Scale (SES) and School Liking and Avoidance Questionnaire (SLAQ).

STUDY 1, the Trauma History Screen-Youth version and PCL-5 were used as tools of survey, and the distribution of children's traumatic event experience was analyzed according to its sociological characteristics. 
Results show as following:
1)Among the children interviewed, 59.35% (n = 4022) experienced at least one traumatic event. Among them, 13.07% (n = 880) children experienced more than 3 types of traumatic events, and 2.24% (n = 151) children experienced more than 5 types of traumatic events. The higher proportion of traumatic events were separation (45.15%), seeing someone badly hurt or killed (17.64%), severe illness (16.90%) and natural disasters (13.93%).
2)Children's traumatic experience is significantly correlated with gender, age, parental out of home and accommodation styles. Male, elder, residence-at-school children with immigrant parents would have higher probability to experience trauma.
3)The positive rate of PTSD symptoms in school-aged children in China is high, accounting for 12.05%. Male [or (95% CI): 1.31 (1.09 - 1.58), P = 0.004], seeing someone badly hurt or killed [1.30 (1.07 - 1.59), P = 0.009], severe illness [1.53 (1.26-1.86), P<0.001], natural disasters [1.35 (1.09 - 1.67), P = 0.005], robbery [2.25 (1.50 - 3.37), P < 0.001], sexual assault [2.73 (1.94 - 3.84), P < 0.001], child abuse [2.33 (1.71 - 3.18), P < 0.001], violence [2.44] (1.82 – 3.27), P < 0.001] seven types of traumatic experience are risk factors for PTSD symptoms, and the more the number of traumatic types, the greater the risk of PTSD symptoms in children.

STUDY 2, PCL-5 and CDI-S were used as tools of survey to investigate the comorbidity of PTSD symptoms and depressive symptoms in children, and the relationship between PTSD symptoms and depressive symptoms. 
Results show as following:
1)Among the children interviewed, the positive rate of screening for depressive symptoms was 16.53% (n = 1004). The comorbidity rate of PTSD symptoms and depressive symptoms was high. Among the children with PTSD symptoms, 35.39% (n = 241) had depressive symptoms at the same time.
2)Both of parents went out to work [1.35 (1.13 - 1.63), P = 0.001], child abuse [1.89 (1.35 - 2.65), P < 0.001], PTSD [2.53 (2.04 - 3.14), P < 0.001] were risk factors for depressive symptoms of children.

STUDY 3, PCL-5 and SES were used as tools of survey to investigate the co-occurrence of PTSD symptoms and low self-esteem, and the relationship between PTSD symptoms and low self-esteem. 
Results show as following:
1)Among the children interviewed, the positive rate of low self-esteem was 13.14% (n = 777). The coincidence of PTSD symptoms and low self-esteem was high. Among the children with PTSD symptoms, 18.71% (n=122) of them had low self-esteem at the same time.
2)Fatal diseases [1.33 (1.07 - 1.65), P = 0.01], violent events [1.48 (1.14 - 1.92), P = 0.04], PTSD symptoms [1.48 (1.14 -1.92), P = 0.003] were risk factors for children's low self-esteem.

STUDY 4, PCL-5 and SLAQ were used as tools of survey to investigate the co-occurrence of children's PTSD symptoms and school avoidance attitude, and the relationship between PTSD symptoms and school avoidance attitudes.
Results show as following:
1)Among the children interviewed, the positive rate of school avoidance attitude was 8.30% (n = 502). The coincidence of PTSD symptoms and school avoidance attitude was high. Among the children with PTSD symptoms, 15.77% (n = 108) of them held school avoidance attitude at the same time.
2)Boys [2.38 (1.88 - 2.94), P < 0.001], parental migration [1.59 (1.24 - 2.03), P<0.001], residence at school [0.64 (0.52 - 0.81), P < 0.001], encounter with sexual assault [2.26 (1.39-3.66), P<0.001] and PTSD symptoms [1.76 (1.29 - 2.38), P < 0.001] can predict children's avoidance attitude towards school.

STUDY 5 analyzed the interrelation and mediation between children's PTSD symptoms, depressive symptoms, low self-esteem and school avoidance attitude. 
Results show as following:
1)PTSD symptoms, depression, low self-esteem and school avoidance attitude are significantly correlated, and PTSD symptoms can significantly and positively predict school avoidance attitude.
2)Depression and low self-esteem play a significant mediating role between PTSD symptoms and school avoidance attitude. Specifically, the first is the mediating role of depression; the second is the mediating role of low self-esteem; the third is the chain mediation of depression and self-esteem.

Based on the previous results, we concluded as followings: 1) the prevalence of traumatic events is high and the types are diverse in the general population of children; 2) after traumatic events, the detection rate of PTSD symptoms, depression symptoms, low self-esteem and school avoidance attitude is high; 3) adolescents with PTSD symptoms are more likely to have depression, low self-esteem and school avoidance attitude at the same time; 4) depression and low self-esteem play as mediatorial role between PTSD symptoms and school avoidance attitude.
In view of the public's insufficient understanding of children's psychological trauma, the lack of psychological resources and the lack of prevention and supervision system, combined with the perspective of child protection, this study puts forward the following policy and practical work suggestions: (1) strengthen the popularization of knowledge about mental health and alleviate the public's incorrect cognition about children's mental health; (2) follow the guidance of evidence-based therapy, develop children's psychological intervention guidelines and innovate the delivery mode of intervention services; (3) take the government as the leading role to build a psychological protection system for children, with the participation of the whole society and multi-sector's cooperation.