Nearly 1 in 5 children have been bullied by peers.² No longer considered a normative behavior of childhood, being bullied by a peer is a major risk factor for a wide spectrum of adverse outcomes in children.³ The rising number of suicides and violence among children who have been bullied makes understanding the causal processes a high priority. Internalizing behaviors, externalizing problems, poor school performance, somatization, and low self-esteem are some of the commonly reported difficulties in children who are bullied. However, the problems are not limited to childhood. Population-based studies demonstrate an enduring effect on mental health outcomes in adulthood long after the bullying has stopped.⁴ Despite these demonstrable associations, it is not known to what extent bullying and mental health are causally linked.

几乎有五分之一的孩子被同龄人欺负。²不再被视为儿童的一种规范行为，被同伴欺负是造成儿童各种不良后果的主要危险因素。³受欺负的儿童中自杀和暴力的数量不断增加，这使得了解因果过程成为当务之急。内在化的行为，外在化的问题，学习成绩差，躯体化和自尊心低下是被欺负儿童中常见的困难。但是，问题不仅限于童年。以人群为基础的研究表明，在欺凌停止后的很长一段时间内，对成年后的心理健康状况产生了持久影响。⁴ 尽管有这些明显的联系，但还不知道欺凌与心理健康在多大程度上因果相关。