Depression Severity Over 27 Months in Adolescent Girls Is Predicted by Stress-Linked Cortical Morphology

Abstract

Background: Evidence supports the notion that early-life stress and trauma impact cortical development and increase vulnerability to depression. However, it remains unclear whether common stressful life events in community-dwelling adolescents have similar consequences for cortical development.

Methods: A total of 232 adolescent girls (mean age 15.29 ± 0.65 years) were assessed with the Stressful Life Events Schedule (a semistructured interview of stressors in the previous 9 months) and underwent a magnetic resonance imaging scan. FreeSurfer 5.3.0 was used to perform whole-brain surface-based morphometry. Dysphoria was assessed at the time of imaging and prospectively at three 9-month follow-up appointments using the Inventory of Depression and Anxiety Symptoms II.

Results: At least one stressful life event was reported in 90% of the adolescent participants during the 9 months preceding imaging. Greater burden of recent life stress was associated with less left precuneus and left postcentral cortical thickness and smaller left superior frontal and right inferior parietal volume (all p < .05 after multiple comparisons correction). Left precuneus thickness in the stress-associated cluster significantly predicted dysphoria for 27 months after imaging controlling for prior dysphoria (β = -.11, p = .004). Left precuneus cortical thickness accounted for 17.0% of the association between stress and dysphoric mood for 27 months after imaging (β = .04, p = .05).

Conclusions: Consistent with evidence from imaging studies of trauma-exposed youths and preclinical stress models, a heavy burden of recent common life stress in community-dwelling adolescent girls was associated with altered frontal/parietal cortical morphology. Stress-linked precuneus cortical thickness represents a candidate prospective biomarker of adolescent depression.

Keywords: Adolescent development; Cortical thickness; Depression; Dysphoric mood; Life stress; Volume.

Figure 1 Caption:

Study timeline for the Adolescent Development of Emotions and Personality Traits (ADEPT) as relevant to this analysis. Abbreviations: SLES: Stressful Life Events Schedule, IDAS-II: Inventory of Depressive and Anxiety Symptoms II. MRI: magnetic resonance imaging, QC: quality control.

Figure 2 Caption:

(A) Surface-based morphometry results surviving multiple comparisons correction for the stress analysis (cluster-wise p < 0.05, corrected). (Left): Thinner left post-central associated with more stress (Left-Center): Smaller left superior frontal associated with more stress (Right-Center): Thinner left precuneus associated with more stress (Right): Smaller right inferior parietal associated with more stress. (B) Partial residual for the IDAS-II Dysphoria scores across Waves 3–5 as estimated from the linear mixed model accounting for age, Wave, Wave², IDAS-II dysphoria score at the time of imaging (Wave 2), and the stress-linked left precuneus cortical thickness estimate. Resulting model standardized beta for the fixed effect of precuneus cortical thickness shown and resulting p-value. (C) Mediation results shown for x = Stressful Life Events Schedule (SLES) total load, M = stress-linked left precuneus cortical thickness, and y = IDAS-II dysphoria score over Waves 3–5. Standardized model beta, p-values, and 95% confidence intervals (CIs) shown.