Supplementary Material for: Cyberbullying and School Bullying Are Related to Additive Adverse Effects among Adolescents

<b><i>Introduction:</i></b> The aim of this study was to examine whether (a) cyberbullying has unique associations with mental health problems, risk-taking, and self-harm behavior in victims and perpetrators when compared to school bullying and (b) if cyberbullying is associated with an additional burden for students already involved in school bullying. <b><i>Methods:</i></b> Data were collected from 6,561 students across 23 schools in Germany (grades 5–13). The sample was divided into the following four groups: cyber-only involvement (victims = 1.9%, perpetrators = 0.6%), school-only involvement (victims = 17.2%, perpetrators = 11.9%), dual involvement (victims = 5.7%, perpetrators = 2.9%), and noninvolvement (victims = 75.3%, perpetrators = 84.6%). Multilevel mixed-effects regression analysis was conducted to examine group differences in mental health (Strengths and Difficulties Questionnaire, KIDSCREEN-10), risk-taking, and self-harm behavior (e.g., substance use, suicide attempts). <b><i>Results:</i></b> Cyber-only bullying had unique associations with mental health problems and risk-taking behavior in victims (lower levels of peer relationship problems: <i>p</i> &lt; 0.001, greater substance use: <i>p</i> &lt; 0.05) and perpetrators (higher levels of peer relationship problems: <i>p</i> &lt; 0.05) when compared to school-only bullying. Dual victims and perpetrators reported significantly more mental health problems (victims: χ²₍₅₎ = 221.58, <i>p</i> &lt; 0.001; perpetrators: χ²₍₅₎ = 116.40, <i>p</i> &lt; 0.001) and were more likely to report risk-taking and self-harm behavior (victims: χ²₍₇₎ = 115.15, <i>p</i> &lt; 0.001; perpetrators: χ²₍₇₎ = 38.79, <i>p</i> &lt; 0.001) than students involved in school-only bullying. <b><i>Conclusion:</i></b> Cyber-only bullying appears to be related to specific mental health issues beyond those associated with school-only bullying. Cyberbullying and school bullying go along with additive mental health problems, risk-taking, and self-harm behavior in both victims and perpetrators. Thus, bullying prevention and intervention programs should also target cyberbullying.

<b><i>引言：</i></b> 本研究旨在探讨两个核心问题：(a) 相较于校园欺凌，网络欺凌在受害者与施害者群体中是否分别与心理健康问题、冒险行为及自伤行为存在独特关联；(b) 对于已卷入校园欺凌的学生而言，网络欺凌是否会为其带来额外的心理负担。
<b><i>研究方法：</i></b> 研究数据采集自德国23所学校的6561名学生（年级跨度为5至13年级）。研究样本被划分为以下四组：仅卷入网络欺凌组（受害者占比1.9%，施害者占比0.6%）、仅卷入校园欺凌组（受害者占比17.2%，施害者占比11.9%）、双重卷入组（同时卷入网络欺凌与校园欺凌，受害者占比5.7%，施害者占比2.9%）以及未卷入任何欺凌组（受害者占比75.3%，施害者占比84.6%）。本研究采用多水平混合效应回归分析，对不同群体在心理健康状况（采用长处与困难问卷（Strengths and Difficulties Questionnaire）、KIDSCREEN-10量表进行评估）、冒险行为及自伤行为（如物质滥用、自杀企图）方面的差异进行检验。
<b><i>研究结果：</i></b> 相较于仅卷入校园欺凌的群体，仅卷入网络欺凌的受害者群体表现出独特的心理健康问题与冒险行为关联（同伴关系问题程度更低：*p* < 0.001，物质滥用程度更高：*p* < 0.05），而仅卷入网络欺凌的施害者群体则表现出更高水平的同伴关系问题（*p* < 0.05）。双重卷入的受害者与施害者群体报告的心理健康问题显著多于仅卷入校园欺凌的群体（受害者：χ²₍₅₎ = 221.58，*p* < 0.001；施害者：χ²₍₅₎ = 116.40，*p* < 0.001），且其报告的冒险行为与自伤行为比例也更高（受害者：χ²₍₇₎ = 115.15，*p* < 0.001；施害者：χ²₍₇₎ = 38.79，*p* < 0.001）。
<b><i>研究结论：</i></b> 仅卷入网络欺凌与仅卷入校园欺凌所关联的心理健康问题存在特异性差异。对于受害者与施害者群体而言，网络欺凌与校园欺凌会共同带来叠加的心理健康问题、冒险行为及自伤行为风险。因此，欺凌预防与干预项目也应将网络欺凌纳入覆盖范围。