Trauma and the Psychological and Physiological Health of Children and Young People in Low- and Middle-Income Countries upd 02/23

儿童和青少年在经历创伤性事件（如身体或性侵犯、灾难、严重事故）后，容易产生一系列心理和社会心理障碍，包括创伤后应激障碍（PTSD）。创伤后应激障碍是非常痛苦的，可以显著影响儿童的社会、教育和长期的身体健康结果。对潜在PTSD生物标志物的研究表明，心率（HR）和心率变异性（HRV；心跳间隔时间的变化）是成人PTSD的特别有力的生物标志物。然而，对儿童和年轻人的有限研究产生了好坏参半的结果，主要是在高收入国家（HIC）的小样本中进行的，这些国家的儿童创伤风险和随后的创伤后应激障碍发病率相对较低。低收入和中等收入国家（LMIC）儿童的创伤后应激障碍（PTSD）研究严重不足，尽管这些人群中创伤性事件和包括创伤后应激障碍在内的精神健康障碍的暴露率很高，但HR尚未作为创伤后应激障碍的生物标志物进行研究。此外，文献中完全缺乏追踪创伤暴露儿童的人力资源变化的纵向研究，尽管它们能够提供人力资源指数与创伤后应激障碍之间联系的关键见解。本博士项目的总体目标是为中低收入儿童提供HR指标作为创伤后应激障碍的短期和长期生物标志物的系统研究，中低收入儿童暴露于严重和复发性创伤的风险更高。将利用两个现有的数据集来实现这一总体目标。首先，通过一项esrc资助的前瞻性纵向研究，从南非开普敦招募了250名8至16岁的创伤暴露儿童的数据，将允许检查：a)创伤后不久的HR指数是否可预测后来的PTSD；b)长期的创伤后应激障碍是否会导致生理变化。其次，来自2004年Pelotas出生队列研究（n=4231）的数据，该研究招募了2004年在巴西南部Pelotas出生的所有儿童，并对6岁、11岁、15岁和18岁的儿童进行了随访，将允许检查：a) HR指数与PTSD之间的关联是否在发育过程中发生变化（例如，在青春期比儿童期更强）；b)先前存在的HR/HRV特征是否会导致创伤暴露后的PTSD易感性；c)是否有在慢性创伤后应激障碍背景下建立的心脏生物标志物。计划对南非斯泰伦博斯大学和巴西圣保罗大学进行海外机构访问，以促进与共同研究人员在数据收集、分析和研究结果传播方面的合作。潜在的应用和益处来自低收入和中等收入国家的儿童和年轻人占世界儿童的大多数，并且不成比例地可能受到创伤的影响。然而，在创伤后应激障碍的证据基础上，他们的代表性严重不足。这个项目有可能对我们理解中低收入儿童创伤后应激障碍的心理生物学基础做出重要贡献。此外，在这一领域尚未应用的纵向方法的使用，将使关于创伤、创伤后应激障碍和自主因素之间的关联的时间性的新颖和重要的问题得到解决。因此，该项目将为儿童创伤的心理和生理后果提供重要的新见解，这是健康和福祉的关键社会决定因素。

AbstractChildren and young people who experience a traumatic event (e.g., physical or sexual assault, disasters, serious accidents) are vulnerable to developing a range of psychological and psychosocial difficulties in the aftermath, including post-traumatic stress disorder (PTSD). PTSD can be extremely distressing and can significantly influence children's social, educational, and physical health outcomes in the long-term. Research investigating potential PTSD biomarkers has indicated that heart rate (HR) and heart rate variability (HRV; the variation in time intervals between heartbeats) are particularly robust biomarkers of PTSD in adults. However, the limited research with children and young people has yielded mixed results and primarily draws on small samples in high income countries (HIC) where risk of child trauma and subsequent rates of PTSD are relatively low. PTSD in children in low- and middle-income countries (LMIC) has been critically understudied, and HR has not been studied as a PTSD biomarker in such populations, despite high rates of exposure to traumatic events and of mental health disorders, including PTSD. Additionally, longitudinal studies that track HR changes in trauma-exposed children are entirely lacking in the literature despite their ability to provide crucial insight into the link between HR indices and PTSD.The overall aim of this PhD project is to provide systematic investigation of HR indices as short- and long-term biomarkers of PTSD among children from LMICs, wherein children are at greater risk of exposure to severe and recurrent traumas. Two existing datasets will be utilised to achieve this overarching aim. Firstly, data from 250 trauma-exposed children, aged 8 to 16 years, from Cape Town, South Africa recruited through a prospective ESRC-funded longitudinal study will allow examination of: a) whether HR indices shortly following trauma are predictive of later PTSD; and b) whether physiological changes emerge over time as a consequence of persistent PTSD. Secondly, data from the 2004 Pelotas birth cohort study (n=4231), which recruited all children born in Pelotas, South Brazil in 2004 and has conducted follow-ups at ages 6, 11, 15 and 18 years, will allow examination of: a) whether associations between HR indices and PTSD change during development (e.g., are stronger in adolescence versus childhood); b) whether pre-existing HR/HRV characteristics lead to vulnerability to PTSD given trauma exposure; and c) whether there are cardiac biomarkers that become established in the context of chronic PTSD. Overseas institutional visits to both Stellenbosch University, South Africa and the University of São Paulo, Brazil are planned to facilitate collaboration with co-researchers regarding data collection, analysis, and dissemination of findings.Potential Applications & BenefitsChildren and young people from LMICs comprise the majority of the world's children and are disproportionally likely to be affected by trauma. However, they are profoundly underrepresented in the PTSD evidence base. This project has the potential to make a crucial contribution to our understanding of the psychobiological underpinnings of PTSD among LMIC children. Moreover, the use of longitudinal methods that have yet to be applied in this field will enable novel and important questions to be addressed regarding temporality of associations between trauma, PTSD, and autonomic factors. This project will thus provide major new insights into the psychological and physiological consequences of childhood trauma, a key social determinant of health and wellbeing.