Abstract
BACKGROUND: Perceived stress in adolescence is a known early marker for later mental health problems, including depression. Yet, its links to traditional and cyberbullying remain understudied, especially in longitudinal research. Gender differences in stress may reflect varying bullying experiences, but this connection is still unclear. This longitudinal study investigated whether victimization by traditional bullying and/or cyberbullying between ages 13 and 15 is associated with increased self-perceived stress, and whether these associations differ by sex or the form of victimization. METHODS: We used data from the baseline (age 13) and two-year follow-up (age 15) surveys of the STARS (Study of Resilience and Stress) cohort in Sweden. The sample included 2099 adolescents (44% male and 56% female). Perceived stress was measured by Cohen’s Perceived Stress Scale, while traditional bullying and cyberbullying victimization were each assessed using a single-item question. Statistical analyses included t-tests, chi-square tests, one-way ANOVAs, and General Linear Models for repeated measures adjusting for confounders in the whole sample, and sex-stratified analyses. RESULTS: Perceived stress increased between ages 13 and 15 for both sexes, with females consistently reporting higher stress levels than males. The prevalence of traditional bullying and cyberbullying victimization rates ranged from 8.2–11.2% and 7.1–9.9%, respectively, and generally declined over the two years. Females were more exposed to cyberbullying victimization at both time points (8.3–9.9%) compared to males (5.3–5.5%). In both sexes, experiencing bullying–whether traditional, cyber, or both–at the age 13, 15 or at both time points was associated with increased stress levels over the two years. The impact on stress persisted even without continued victimization. Although overall patterns were similar between males and females, being cyberbullied at age 15 was specifically associated with increased stress among females, but not males. Changes in stress levels were similar across both forms of victimization. CONCLUSIONS: Exposure to traditional and/or cyberbullying at age 13, 15, or across both time points is associated with increased perceived stress over time in both males and females, highlighting the potentially lasting impact of victimization on adolescent stress trajectories and the importance of preventive and supportive interventions. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-026-26395-4.