The Impacts and Interventions of School Bullying

. The large prevalence of school bullying and its adverse impacts have drawn strong societal interest. Abundant research has revealed that bullying victimisation and perpetration are harmful to children’s mental well-being. The negative effects could even persist in their adulthood. Hence, many school-based anti-bullying interventions were developed and evaluated. However, cases of school bullying are still constantly emerging nowadays. This paper aimed to delve into this issue by reviewing previous literature, describing the short-term and long-term impacts of school bullying, and evaluating anti-bullying interventions. The results demonstrated that bullying victimisation and perpetration predicted mental disorders in both childhood and adulthood. The whole-school intervention could effectively alleviate bullying victimisation, although had limited effects on reducing bullying perpetration. This paper systematically summarised key findings in the past 20 years on the topic of school bullying. The findings emphasized that the involvement of both schools and families, participation of a wide population, and specifically tailored interventions were essential to reduce bullying victimisation and perpetration.


INTRODUCTION
Bullying is defined as repeated aggressive behaviour characterised by an observed or perceived power imbalance between the victim and perpetrator [1].Hicks et al. classified bullying behaviours into two modes (i.e., direct and indirect) and four types (i.e., physical, verbal, relational, and property damage) [2].Direct bullying is referred to as bullying that is overt and in the presence of a target victim.Whereas, indirect bullying uses covert means, like spreading rumours about the victim.
The phenomenon of school bullying has persisted for years and had a large prevalence.Chudal et al. showed that traditional school bullying has been observed in 13 European and Asian countries [3].Thus, school bullying has become a global issue and is affecting children all over the world.
It was demonstrated that school bullying can have profound and long-term consequences for everyone involved [1].Moreover, childhood victimisation was strongly associated with psychiatric disorders in adulthood, such as anxiety and depression [4].However, there has been a lack of studies that listed the short-term and long-term consequences of bullying victimisation and bullying perpetration.Thus, this paper would describe the short-term and long-term impact of bullying on victims and bullies in detail.
Because of the high incidence of mental health problems among bully victims and bully perpetrators, researchers have actively investigated and evaluated various school-based anti-bullying interventions.The most successful intervention method -the whole-school approachwas firstly adopted by Olweus Programme in Norway and achieved great success (i.e., reduced bullying behaviour by around 50%) [5].However, this level of success has yet to be replicated elsewhere [6].For instance, the wholeschool approach failed to reduce bullying behaviour in Rogaland [7].Hence, the effectiveness of the whole-school approach was equivocal when generalising in different areas.Therefore, this paper aimed to review components that are essential for successful intervention outcomes and evaluate the effectiveness of the intervention that used the whole-school approach, typically in primary and secondary schools.

The Impact of Bully Victims
One of the most evident psychological symptoms of bullying among bully victims is depression.According to Fekkes et al., peer victimisation was strongly related to anxiety and depressive disorders in school-age children [8].This association could be explained by a mediator: emotion dysregulation.For bully victims, frequent victimisation experiences may cause emotion dysregulation, which means the inability to process negative emotions [9].Because managing the negative emotions elicited by victimisation requires significant effort, nearly no mental resource is left for self-regulation and dealing with subsequent negative emotions.Consequently, accumulating internalizing symptoms (sadness, anxiety, and loneliness) due to emotion dysregulation might lead to depression [10].
In the meantime, the reciprocal relations between depression and victimisation indicated that depression might further impair the ability of social information processing which resulted in victimisation [11].For example, depressed adolescents may anticipate that others will be rejective or hostile, although it is a neutral or even positive perceived by others.Depressive adolescents who have distorted social information processing and impaired social skills may become easy targets for bullies [12].
Despite the depressive symptoms mentioned above, other consequences of peer victimisation could be increasing self-harm behaviours, and decreasing self-rated physical health and life satisfaction.Specifically, the meta-analysis by Karanikola et al. indicated a positive relationship between self-harm and peer victimisation [13].Depressive symptoms might act as a mediator of this association, although its role in this relationship was equivocal and future studies are required.In addition, a dose-response relationship between bullying victimisation and self-harm behaviours has been supported by several studies [13].This indicated that more frequent victimisation experiences could result in more self-harm behaviours.Furthermore, bullying victimisation might cause poor self-rated health and life satisfaction [14].The association could be partially mediated by relationships with teachers, families, and peers [14].

The Impact of Bully Perpetrators
Bullying perpetrators who are easy to be overlooked in literature are also associated with adverse psychological outcomes, like depression and self-harm behaviours in the short term.Naveed et al. explained that the high risk of depression in perpetrators might be because they blame themselves for causing harm to others [15].In addition, bullies who showed frequent aggressive behaviours might have a low functional capacity, because they had little control over their behaviours and emotions.Longitudinal research done by King et al. demonstrated that bully perpetrators revealed evident functional impairment specifically related to emotions, and were more likely to report major depression and depressive conduct disorder [16].

The Impact of Bully Victims
Bullying perpetration and victimisation that happened in childhood had an adverse and chronic effect on one's life, and different psychiatric disorders could present in early adulthood [17].Gladstone et al. proposed that anxiety disorders were comorbidities of depression among adult patients who have been victimised by childhood bullying [18].In addition, the history of childhood bullying was correlated with an increased risk of depression in one's adulthood [19].Moreover, the longer, more intensive, and more frequent the bullying victimisation was, the more severe the depression would be [19].Therefore, it is clear from the empirical evidence that the experience of school bullying victimisation would cause a series of mental dis-orders (i.e., anxiety disorders, depression) and psychological symptoms (i.e., social anxiety, stress, suicidal ideation) on one's psychological well-being later in life.

The Impact of Bully Perpetrators
Similarly, negative psychological well-being later in life could be attributed to bullying perpetration in childhood and adolescence.For example, frequent bullying perpetration at the age of eight predicted antisocial personality, depressive and anxiety disorders at ages 18 to 23 [20].A survey conducted with US adults suggested that bullying perpetration was a precursor of potential antisocial behaviour syndromes like conduct disorder and antisocial personality disorder [21].Individuals with a history of bullying had a higher likelihood to develop a conduct disorder and an antisocial personality disorder than their non-bullying peers, even after controlling for other variables like family history of antisocial behaviour and sociodemographic.Moreover, the history of bullying might be also associated with cannabis use disorder, alcohol use disorder, and nicotine dependence in adulthood, although the relationship was modest [21].

Intervention Approaches to Bullying
A recent meta-analysis evaluated the effectiveness of over 80 school-bullying intervention programs and indicated several intervention components that were crucial to intervention outcomes [22].For example, informal peer involvement like group discussions or role-playing activities reduced bullying perpetration by about 12.5% and bullying victimisation by 9%.Furthermore, teachers' attitudes towards bullying and parents' knowledge about bullying were also essential components of the anti-bullying intervention.Importantly, it was demonstrated that the wholeschool approach which included these components collectively could reduce bullying perpetration (about 11%) significantly more than the single-component approach that did not include all components (about 5%) [22,23].The Australian Friendly Schools project (FS) was one of the first empirical longitudinal studies that evaluated the whole-school approach [24].The FS intervention that used the whole-school approach was the experimental condition of the FS project.The intervention was shown to be successful in reducing bullying behaviours in schools based on empirical evidence.
The FS intervention involved the participation of the whole-school community, students' families, teachers, and students themselves [25].Specifically, at the level of the whole school, a team of several key staff was trained to plan and implement bullying-related policy, prevention, and management activities.The team also supervised the intervention process by reviewing the data collected from students.At the family intervention level, complementary home activities were required to be completed by parents, which aimed to raise parents' awareness and utility knowledge about school bullying.Parents were also trained to communicate with children about their bullying experiences, and helped children prevent and manage to bully.At the classroom intervention level, learning activities were designed to facilitate students' knowledge, attitudes, and skills about bullying.Students were taught to develop pro-social skills, interpersonal problem-solving abilities, and empathy for bullied individuals.Teachers also received professional training to improve their skills, so that they could deliver bullying-related teaching and intervene in bullying incidents.

The Effectiveness of The Bullying Intervention
FS intervention was suggested to be beneficial in reducing bullying victimisation in primary school students [25].The FS intervention was effective at the end of both the first and second years of the intervention.Students in the FS intervention group had fewer bullying victimisation experiences than students in the comparison group who received standard health education curriculum only.Students in the FS intervention group also reported that they were less likely to see another student being bullied, compared with the comparison group.Moreover, the FS intervention was significantly effective in encouraging bully victims to seek support by talking to someone about the bullying.Therefore, it was clear that FS intervention was particularly effective in reducing bullying victimisation and facilitating the help-seeking abilities of bully victims.
The positive impact of FS intervention also appeared in secondary school students.Grade 8 students are in a transition phase from primary to secondary school [23].The increasing reliance on peers for social support and more stress to achieve a social status which can lead to more frequent bullying among secondary school students [26].Moreover, secondary school students who struggle to make friends may feel isolated and anxious.Cross et al. found that FS intervention could effectively address these issues [23].The FS intervention successfully prevented the increase of bullying victimisation and perpetration.Accordingly, students also felt safer and had lower levels of negative emotions (i.e., depression, anxiety, stress, and loneliness).
However, FS intervention did not always have a significant effect on reducing bullying perpetration.Cross et al. explained that it could be due to the limited age group involved in the intervention [25].For the FS intervention conducted in primary schools, because only the Grade 4 students cohort was involved, the effectiveness of the intervention was limited by the cohort size.Hence, cohorts in all grades might need to participate in the intervention, especially given about 20% of Grade 4 students reported that they were bullied by students from Grade 5 and 6.Despite the population size, it was also suggested that treatments that are specifically tailored to students of different ages, and with various social and psychological characteristics were required to address bullying perpetration [25].Therefore, interventions targeting different ages and characteristics of students are required to be implemented and evaluated by future studies.

CONCLUSION
As shown in previous research, childhood school bullying had detrimental effects on both bully victims and bully perpetrators.In the short-term, experience of bullying victimisation undermined both the mental (i.e., depression) and physical health (i.e., decreased self-rated physical health) of bully victims.In turn, depression further impaired the social information processing of victims and made them become future bullying targets.Likewise, increasing depressive symptoms, self-harm behaviours, and low functional capacity appeared among bully perpetrators.Bully perpetrators with previous victimisation experience were in the worst mental health condition and experienced the most frequent psychological symptoms.Furthermore, bullying victimisation and perpetration which happened in one's childhood had a long-lasting effect.Specifically, frequent childhood victimisation predicted some mental disorders and psychological symptoms presented in adulthood.
To alleviate childhood school bullying, previous research has evaluated many anti-bullying interventions and suggested the whole-school approach as the most effective method.The Friendly School (FS) intervention which used the whole-school approach integrated intervention at three levels: school level, family level, and classroom level.In both primary and secondary schools, the FS intervention succeeded in reducing bullying victimisation and relieved psychological symptoms of victims, although it did not evidently reduce bullying perpetration.The possible reason could be that the number of children involved was not enough, and children with different ages and characteristics might require different interventions.
This paper reviewed previous literature about school bullying in the past 20 years and summarised key findings about the impact of school bullying and the effectiveness of anti-bullying interventions.The results emphasised the severe impacts of school bullying on children's mental health and development.Hence, schools should actively adopt successful anti-bullying interventions like FS intervention in all grades as soon as possible.Future studies are required to evaluate the effectiveness whole-school approach in different contexts and develop more specialised interventions accordingly.