Sleep-Impulsivity-Behaviour (SIB) Study: examining mechanisms underpinning self-harm in children with autism and intellectual disability

自残行为，如咬人、抓挠、撞头和打身体，在自闭症和智力残疾儿童中发生率很高。多达1 / 2的患有自闭症和本症的儿童会自残，在大多数情况下，这些行为会持续到童年以后。不幸的是，自残是家庭压力的主要原因，经常导致安置破裂，导致儿童需要远离家庭的专业住宿安置。我们对自闭症儿童的自残和ID的现有理解表明，环境和内部感官体验的相互作用可以引起和维持自残。例如，要求孩子完成学校的任务可能会导致孩子咬自己；一个关心的成年人可能会暂时放弃安慰和保护孩子的任务。随着时间的推移，一个微妙的学习过程发生了，它将孩子和周围环境之间的这些相互作用嵌入其中。这种学习过程使自残的可能性更大，也会使自残更加严重。然而，虽然这种自残模式是有帮助的，但它并没有识别出这些学习过程之外的自残的潜在原因。此外，基于这种模式的干预通常只能在自残已经成为一种习得行为之后开始。我们的工作将揭示推动这一学习过程的原因，并导致针对原因的干预措施，以防止自残成为既定的。基于我们之前的研究，睡眠冲动行为（SIB）研究调查了自残的两个潜在原因或驱动因素。首先，我们研究一个基本的基于大脑的机制。我们的研究表明，自残的孩子在停止和开始自己的行为方面存在问题；这种基于大脑的机制被称为抑制。然而，对于患有自闭症和并发性认知障碍的儿童来说，目前对抑制作用的评估往往太长或太困难。我们已经开发了新的，专门的抑制测试，可以用于自闭症和ID儿童，使我们能够测试抑制问题是否是自我伤害的根本原因。这些新的测试是快速和简单的基于游戏的游戏，我们将比较自闭症和ID儿童在这些游戏中的表现，他们有自残的表现，没有自残的表现。其次，我们调查了睡眠不足是否会增加自残的可能性。我们特别感兴趣的是特定的睡眠困难，例如入睡问题，保持睡眠问题，或者在24小时周期中的错误时间睡觉的问题，是否会导致更频繁和更严重的自我伤害。我们将使用腕上佩戴的睡眠设备直接评估儿童的睡眠，提供关于睡眠时间和睡眠持续时间的准确信息。我们将使用先进的统计模型将儿童的睡眠数据与他们的自残信息联系起来，这些数据由父母/照顾者通过手机应用程序收集。我们的分析将提供关于睡眠对自残影响的结论性信息。为了完成SIB研究，我们将把这两方面的工作结合起来。在正常发育的儿童和成人中，睡眠会影响抑制作用。因此，我们认为抑制可以部分解释睡眠质量差和自残之间的关系。在我们的最后一项研究中，我们将通过运行睡眠干预来测试这个想法，以改善自闭症和ID儿童的睡眠。我们将测量抑制和自残看看抑制的改善能否解释自残的一些变化。总之，这三项研究将表明，抑制能力差和睡眠质量差是否会导致自闭症和ID儿童的自我伤害。研究结果将为自我伤害的干预提供信息，将睡眠和抑制作为新的预防性干预目标。通过我们与临床服务和政策制定者的广泛联系，我们将确保该项目的研究结果迅速有效地影响临床实践。

Self-harm, such as biting, scratching, head banging and body punching, occurs at very high rates in children with autism and intellectual disability (ID). As many as 1 in 2 children with autism and ID will self-harm, and in most cases these behaviours persist beyond childhood. Unfortunately, self-harm is a primary cause of family stress, and often leads to placement breakdown resulting in children requiring specialist residential placements away from the family home. Our existing understanding of self-harm in children with autism and ID suggests that interactions in the environment and internal sensory experiences can cause and maintain self-harm. For example, asking a child to complete a school-based task may lead to the child biting themselves; a concerned adult may then briefly remove the task to comfort and protect the child. Over time, a subtle learning process occurs which ingrains these interactions between the child and the environment around them. This learning process makes self-harm more likely, and can also make it more severe. However, whilst this model of self-harm is helpful, it does not identify underlying causes for self-harm beyond these learning processes. Additionally, interventions based on this model can typically only be started after self-harm has already become a learnt behaviour. Our work will uncover causes that drive this learning process, and lead to interventions that target causes to prevent self-harm from becoming established.Based on our previous research, the Sleep-Impulsivity-Behaviour (SIB) Study investigates two potential causes or drivers of self-harm. First, we examine a fundamental brain-based mechanism. Our work suggests that children who self-harm have problems stopping and starting their own behaviour; this brain-based mechanism is called inhibition. However, current assessments of inhibition are often too lengthy or too difficult for children with autism and a co-occurring ID. We have developed new, specialised tests of inhibition that can be used with children with autism and ID, allowing us to test whether problems with inhibition are a fundamental cause of self-harm. These new tests are quick and easy play-based games, and we will compare performance on these games in children with autism and ID who do, and do not show self-harm.Second, we investigate whether poor sleep makes self-harm more likely. We are particularly interested in whether specific sleep difficulties, for example problems with falling asleep, problems with staying asleep, or problems with sleeping at the wrong time in a 24-hour cycle, lead to more frequent and more severe self-harm. We will use wrist worn sleep devices to directly assess children's sleep, providing accurate information about sleep timing and sleep duration. We will use advanced statistical modelling to link children's sleep data with information about their self-harm, collected by parents/carers via a mobile phone App. Our analysis will provide conclusive information about the influence of sleep on self-harm.To complete the SIB Study, we will bring together these two strands of work. In typically-developing children and adults, sleep is known to influence inhibition. Therefore, we think that inhibition may explain part of the relationship between poor sleep and self-harm. In our final study, we will test this idea by running a sleep intervention to improve sleep in children with autism and ID. We will measure inhibition and self-harm to see if improvements in inhibition explain some of the changes in self-harm. Together, all three of these studies will show whether poor inhibition and poor sleep cause self-harm in children with autism and ID. Findings will inform interventions for self-harm, with sleep and inhibition as new, preventative intervention targets. Through our extensive links with clinical services and policy makers, we will ensure that the findings of this project quickly and effectively influence clinical practice.