In the planned systematic review and meta-analysis we will focus on the consequences of bullying perpetration on mental health, somatic health, academic functioning, and social functioning. The following outcome categories will be analyzed separately: internalizing problems, externalizing problems, somatic problems, psychotic/schizophrenic problems, substance use, eating disorders, academic functioning, well-being/happiness, and positive social functioning. We will separately analyze bullying perpetrators and bullying perpetrators who are also victims of bullying (i.e., bully-victims) and childhood and adolescent bullying perpetration will also be analyzed separately. We expect homogeneous effects for bully-victims, namely generally disadvantageous outcomes, and more heterogeneous effects for bullying perpetrators. If reported in a sufficient number of studies, or if the relevant data can be acquired from the authors, we will in our meta-analyses adjust for baseline measures of the outcome variables.
The meta-analysis on outcome substance use was published in *Pediatrics*:
Vrijen C, Wiertsema M, Ackermans MA, et al. Childhood and Adolescent Bullying Perpetration and Later Substance Use: A Meta-analysis. Pediatrics. 2021;147(3):e2020034751. DOI: https://doi.org/10.1542/peds.2020-034751