Scientific interest in lesbian, gay, bisexual, transgender, queer and any other sexual orientation, gender identity and/or expression (LGBTQ+) bullying in educational settings has grown exponentially in recent years. However, the varied ways of measuring its occurrence and associated factors have made it difficult to achieve a holistic understanding of this problem. Therefore, this systematic review aimed to provide an updated overview of individual and contextual factors related to LGBTQ+ bullying over the past two decades, based on the measurement approach to this phenomenon. Studies published from 2000 to 2020 were analyzed following the Preferred Reporting Items for Systematic reviews and Meta-Analyses strategy. Inclusion and exclusion criteria were applied in a staggered process, and 111 articles met all the criteria. Studies focusing on LGBTQ+ bullying victimization or aggression were eligible for inclusion. Our analysis revealed LGBTQ+ bullying is usually examined by measures of general aggressions (47.8%) from the victims' perspective (87.3%). The best-represented factors across studies were individual characteristics (63.1%; n = 70), especially participants' sexual orientation and gender identity and expression (68.5%). Boys/males, from a binary gender perspective, and sexual and gender minority youth in general, were more at risk of being targeted for LGBTQ+ bullying. Although contextual factors were far less well-represented, the results revealed that gay-straight alliances, anti-homophobia policies, and social support act as protective factors. This review highlights the need to analyze LGBTQ+ bullying considering the full spectrum of sexual and gender diversity, to examine in more detail its contextual risk/protective factors, and to design public policies and psychoeducational programs in order to address the low effectiveness of generic interventions. Implications for future research and practice are discussed.
Keywords: LGBTQ+; aggression; bullying; protective factors; risk factors; systematic review; victimization.