Symposium: Advancing Sex- and Gender-Based Research: Transitions Over the Life Course for Understanding Young Women’s Risk for Affective Psychopathology.
Background: Early life stress (ELS) is associated with heightened risk for a range of psychosocial difficulties in adolescence, including depression (LeMoult et al., 2019), often to a greater degree in females (Goodwill et al., 2018). We have demonstrated that ELS selectively affects frontolimbic white matter (WM) circuitry in males and females, and depressive symptoms, during early puberty (Kircanski et al., 2019). Here, we tested whether ELS is differentially associated with age-related changes in whole-brain WM morphometry, and internalizing and externalizing problems in boys and girls during this critical period of neurodevelopment.
Method: We conducted comprehensive interviews assessing lifetime exposure to stress with 220 participants (123 females) ages 9¬–14 years (Ribbe, 1996) and rated the objective severity of each stressor endorsed, yielding a cumulative ELS severity score (King et al., 2017). We assessed internalizing and externalizing behaviors with the Youth Self-Report (Achenbach, 1991). A diffusion-weighted MRI scan was acquired to examine WM fixel-based morphometry, a combined measure of fiber density and cross-section (FDC; Raffelt et al., 2017).
Results: Across all participants, age was positively associated with FDC of several tracts (e.g., bilateral corticospinal, superior longitudinal fasciculi (SLF), corpus callosum [CC], ps<.05). Only males showed increases with age in FDC of the forceps minor and bilateral inferior longitudinal fasciculi (ILF), ps<.042. Multivariate analyses indicated that whereas younger females reported more internalizing problems than did younger males, older males and females did not differ from each other. Younger, but not older, females also showed a positive association between forceps minor and uncinate FDC and both internalizing and externalizing problems (ps<.05). Younger, but not older, males showed a positive association between SLF FDC and these problems, and a negative association between ILF FDC and these problems (ps<.05). Finally, among participants with greater ELS, females had lower CC FDC than did males (p=.003).
Conclusions: Distinct neurodevelopmental mechanisms may contribute to sex differences in the emergence of psychopathology during early puberty, particularly in adolescents who have experienced early adversity.