Abstract
BACKGROUND: Anxiety is the most common mental health problem in young people and sex/gender differences have been consistently reported, with girls and young women experiencing twice the chance of anxiety compared to boys and young men. There is a limited understanding, however, of the underlying causes of these differences. This systematic review aims to synthesise research identifying modifiable sex/gender-specific risk and protective factors for anxiety among young people aged 16–24 in high income countries. METHODS: A systematic literature search was conducted on 29th February 2024 and updated on 4th July 2025 across MEDLINE (Ovid), PsycINFO (Ovid), EMBASE (Ovid), Scopus, Sociological abstracts, and Web of Science. Observational studies reporting estimates of sex/gender-specific associations between modifiable risk and protective factors and anxiety according to DSM-5 categories were included. Results were summarised using narrative synthesis. RESULTS: 85 studies were included. Modifiable factors were grouped into levels: individual; interpersonal relationships; local community; and wider environment and society levels. The review identified conflicting results for sex/gender differences, demonstrating the methodological limitations of the evidence base and the complexity of the modifiable risk and protective factors implicated in the explanations for sex/differences in anxiety among young people aged 16–24 years. Potential sex/gender-specific risk factors emerged; early alcohol use initiation, parental overprotection and social media may be more anxiety-inducing in females than in males. CONCLUSIONS: This review indicates that sex/gender differences may exist in the associations between modifiable risk and protective factors and anxiety. Future longitudinal studies are crucial to understanding how these pathways differ by sex/gender. Studies are needed which explore whether sex/gender influences the relationship between anxiety and gender discrimination, peer relationships, school/college context, the workplace and the school-to-work transition. Such evidence has the potential to guide the development of effective sex/gender-specific mental health interventions. PROSPERO PROTOCOL REGISTRATION: CRD42024518279. CLINICAL TRIAL NUMBER: Not applicable. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-026-26447-9.