Self-harm in secondary schools; Prevalence, School Level Influences, and Interventions

Abstract

The majority of young people who self-harm will not present to health care services, allowing schools to play a key role in identifying and potentially supporting young people who self-harm to access help. In this thesis, I present my research on self-harm in schools, focusing on prevalence of self-harm in schools, schools level influences, including broader school factors and individual school experiences, and school-based interventions. I begin by providing an overview of self-harm definitions, the epidemiology of self-harm, frameworks to understand self-harm, existing risk factors for self-harm, and the role of schools. My first study presents nationally representative estimates of the prevalence of self-harm and individual factors associated with self-harm in a large study of secondary school students. The prevalence of self-harm in 11 – 15 year olds in 2017 was 15.6% (95% CI 13.4 – 18.0), which increased to 17.7% (95% CI 16.8 – 19.0) in 2018, 19.9% (95% CI 18.6 – 21.0) in 2019, and 22.9% (95% CI 20.4 – 25.0) during the peak of the COVID-19 pandemic in 2020. Compared to boys, girls had approximately 116% higher odds of self-harm and the gender diverse group had 167% higher odds of self-harm. The second study focuses on school level factors and individual factors associated with self-harm; this analysis was conducted with the same dataset used to calculate nationally representative prevalence. Key findings showed self-harm varied across schools ranging from 0% – 20%. For each one-unit increase in the pupil school climate scores, the odds of self-harm decreased by 50%. The third study focuses on the role of self-reported school experiences and self-harm in a large cross-sectional survey of secondary school pupils. Key findings showed school experiences associated with greater self-harm included believing that their school does not deal with bullying and racism, and feeling picked on by a teacher. Additionally, feeling adults in school do not listen to the students’ opinions was also associated with a greater likelihood of self-harm. The final study is a systematic review of school-based interventions addressing self-harm in students. Key findings showed a huge evidence-gap in the support of young people who are self-harming in educational settings. Interventions delivered by external agencies also seemed to be more effective and the included studies reported no iatrogenic effects, which could be taken as tentative evidence that directly addressing self-harm in the school environment does not appear to increase self-harm behaviour. Strengths of the PhD include the use of two large school-based datasets with validated measures of mental health, wellbeing, and school climate. As well as continued input and involvement from young people with lived experience of self-harm and the people who support them. Despite using relatively large datasets, the sample size of gender diverse young people was small, resulting in substantial missing data. In future, oversampling from these communities and using multiple imputation could assist in resolving this issue. Future research into schools and self-harm should focus on tractable factors and universal and targeted interventions to address issues such as bullying and poor school climate as well as improved support for groups more vulnerable to self-harm including girls and gender diverse young people.