Susceptibility or Resilience to Maltreatment Can Be Explained by Specific Differences in Brain Network Architecture.

BACKGROUND: Childhood maltreatment is a major risk factor for psychopathology. However, some maltreated individuals appear remarkably resilient to the psychiatric effects while manifesting the same array of brain abnormalities as maltreated individuals with psychopathology. Hence, a critical aim is to identify compensatory brain alterations that enable resilient individuals to maintain mental well-being despite alterations in stress-susceptible regions.
METHODS: Network models were constructed from diffusion tensor imaging and tractography in physically healthy unmedicated 18- to 25-year-old participants (N = 342, n = 192 maltreated) to develop network-based explanatory models.
RESULTS: First, we determined that susceptible and resilient individuals had the same alterations in global fiber stream network architecture using two different definitions of resilience: 1) no lifetime history of Axis I or II disorders, and 2) no clinically significant symptoms of anxiety, depression, anger-hostility, or somatization. Second, we confirmed an a priori hypothesis that right amygdala nodal efficiency was lower in asymptomatic resilient than in susceptible participants or control subjects. Third, we identified eight other nodes with reduced nodal efficiency in resilient individuals and showed that nodal efficiency moderated the relationship between maltreatment and psychopathology. Fourth, we found that models based on global network architecture and nodal efficiency could delineate group membership (control, susceptible, resilient) with 75%, 82%, and 80% cross-validated accuracy.
CONCLUSIONS: Together these findings suggest that sparse fiber networks with increased small-worldness following maltreatment render individuals vulnerable to psychopathology if abnormalities occur in specific nodes, but that decreased ability of certain nodes to propagate information throughout the network mitigates the effects and leads to resilience.