Structural Brain Correlates of Multidomain Resilience Among Youth Exposed to Neighborhood Disadvantage

Abstract

Background: Many youth exposed to adversity exhibit resilience, yet the neurobiological factors that support resilience are poorly understood. Few studies have examined how brain structure is related to resilience across multiple domains of functioning.

Methods: We evaluated associations between brain structure (volume, thickness, surface area) and psychological, social, and academic resilience in a sample of 708 twins (7-19 years) exposed to neighborhood disadvantage from the Michigan Twin Neurogenetics Study, recruited from the Michigan State University Twin Registry.

Results: For youth exposed to neighborhood disadvantage, greater total gray matter volume predicted positive psychological adaptation, while smaller right caudal middle frontal gyrus surface area predicted positive social adaptation. We examined whether cumulative adverse experiences moderated the relationship between brain structure and positive outcomes. Several interactions between brain structure and cumulative risk were found to predict positive outcomes, yielding multidomain resilience. Generally, larger brain structure correlated with increased positive functioning in specific domains for individuals with high cumulative risk but not for those with low cumulative risk.

Conclusions: The study supports the use of multidomain resilience models and identifies neural mechanisms that may promote adaptive responses to adversity. Most identified structural correlates of positive adaptation were indicators of resilience in that they predicted positive function at moderate to high levels of exposure to cumulative risk.

Keywords: Adolescence; Brain structure; Cumulative risk; Neighborhood disadvantage; Resilience.

Figure 1

Area Deprivation Index (ADI) scores in the MTwiNS (Michigan Twins Neurogenetics Study) sample. N = 708. ADI scores measure concentrated disadvantage in the neighborhood via 17 indicators of neighbors’ education, employment, income, and poverty (e.g., home ownership rates, percentage of single-parent households, percentage of families living below the poverty line, percentage of those ≥17 years old unemployed). ADI scores are derived from the American Community Survey 5-Year Estimates and provide a national percentile ranking at the block group level from 1 to 100 with group 1 reflecting the lowest level of disadvantage in the nation, whereas group 100 represents the highest level of disadvantage. In the MTwiNS sample, 90% of youth live in neighborhoods with ADI scores of ≥30, and nearly 80% live in neighborhoods with ADI scores of ≥40.

Figure 2

Multidomain model of positive functioning. All factor loadings are from the standardized solution. Based on modification indices, residual variances for parent and youth activities report and parent activities report and social competency were allowed to covary. Standard errors of factor loadings are represented in parentheses. All factor loadings and covariances were significant at p < .001. Root mean square error of approximation = 0.05, comparative fit index = 0.93, standardized root mean residual = 0.05. Child-report forms include the Child and Youth Resilience Measure (CYRM), Satisfaction With Life Scale (SWLS), and Youth Self Report (YSR). Parent-reported forms include the Child Behavior Checklist (CBCL). Teacher-report forms include the Teacher Report Form (TRF). [Reprinted and adapted with permission from Bezek et al. (28).]

Figure 3

Global and regional brain structure predicts positive adaptation at different levels of cumulative risk. N = 708. We visualized the simple slopes of significant interactions using the Preacher Interactions online tool at different levels of cumulative risk (−1 SD, mean, +1 SD). The range of observed values of cumulative risk is −1.13 to 4.87. The shaded rectangles represent regions of statistical significance for the interactions. (A) Total gray matter volume × cumulative risk predicts psychological adaptation: slope is significant when cumulative risk is outside the interval −3.50 to −0.02. Twenty-five percent of twins reported that their cumulative risk was above this interval and had total gray matter volume <1.51 mm³. (B) Mean surface area × cumulative risk predicts psychological adaptation: slope is significant when cumulative risk is outside the interval −2.14 to 0.21. Twenty-one percent of twins reported that their cumulative risk was above this interval and had mean surface area <1.49 mm². (C) Left (L) lateral orbitofrontal surface area × cumulative risk predicts psychological adaptation: slope is significant when cumulative risk is outside the interval −1.93 to 0.58. Twenty percent of twins reported that their cumulative risk was above this interval and exhibited L lateral orbitofrontal surface area <1.54 mm². (D) Right (R) lateral orbitofrontal surface area × cumulative risk predicts psychological adaptation: slope is significant when cumulative risk is outside the interval −1.49 to 0.61. Nineteen percent of twins reported that their cumulative risk was above this interval and exhibited R lateral orbitofrontal surface area <1.50 mm². (E) R rostral anterior cingulate surface area × cumulative risk predicts psychological adaptation slope is significant when cumulative risk is outside the interval −0.90 to 0.83. Fifteen percent of twins reported that their cumulative risk was above this interval and exhibited R rostral anterior cingulate surface area <1.41 mm². (F) L amygdala volume × cumulative risk predicts psychological adaptation: slope is significant when cumulative risk is outside the interval −1.55 to 0.72. Sixteen percent of twins reported that their cumulative risk was above this interval and exhibited left amygdala volume <1.36 mm³. (G) L nucleus accumbens volume × cumulative risk predicts psychological adaptation: slope is significant when cumulative risk is outside the interval −0.82 to 1.40. Twenty-four percent of twins reported that their cumulative risk was below this interval and exhibited L nucleus accumbens volume <1.41 mm³. Seven percent of twins reported that their cumulative risk was above this interval and exhibited L caudate volume <1.02 mm³. (H) R putamen volume × cumulative risk predicts psychological adaptation: slope is significant when cumulative risk is outside the interval −0.94 to 1.92. Twenty-two percent of twins reported that their cumulative risk was below this interval and exhibited R putamen volume <1.80 mm³. Three percent of twins reported that their cumulative risk was above this interval and exhibited R putamen volume <1.80 mm³. (I) L caudate volume × cumulative risk predicts social adaptation: slope is significant when cumulative risk is outside the interval −2.40 to 0.002. Sixteen percent of twins reported that their cumulative risk was above this interval and exhibited L caudate volume <0.40 mm³. (J) R caudate volume × cumulative risk predicts social adaptation: slope is significant when cumulative risk is outside the interval −2.06 to 0.11. Thirteen percent of twins reported that their cumulative risk was outside of this interval and exhibited R caudate volume <0.35 mm³. (K) R rostral middle frontal gyrus thickness × cumulative risk predicts academic adaptation: slope is significant when cumulative risk is outside the interval −2.44 to 0.75. Twelve percent of twins reported that their cumulative risk was above this interval and exhibited R rostral middle frontal gyrus thickness <0.28 mm.