Bullying victimization and brain development: a longitudinal structural magnetic resonance imaging study from adolescence to early adulthood.

This study investigated associations between bullying victimization and brain development using longitudinal structural MRI data from the IMAGEN cohort (n = 2094; 1009 females) across three time points (∼14, ∼19, and ∼22 years). A data-driven analysis revealed that higher bullying victimization was significantly associated with accelerated volumetric growth in subcortical and limbic regions, including the putamen (β = 0.12, 95% CI: 0.10-0.15), amygdala (β = 0.07, 95% CI: 0.05-0.09), hippocampus (β = 0.06, 95% CI: 0.04-0.08), and anterior cingulate cortex (caudal: β = 0.05, 95% CI: 0.03-0.07; rostral: β = 0.06, 95% CI: 0.04-0.08). In contrast, bullying victimization was also significantly associated with reduced volumetric growth in the cerebellum (β = -0.09, 95% CI: -0.11 to -0.07), entorhinal cortex (β = -0.10, 95% CI: -0.13 to -0.07), and insula (β = -0.08, 95% CI: -0.11 to -0.06). Exploratory analyses indicated that females exhibited more pronounced changes in emotional processing regions, while males showed greater changes in motor and sensory areas. Overall, the findings indicate that bullying victimization is associated with widespread structural differences in brain development from adolescence to early adulthood, with sex-specific trajectories.