Type and timing of childhood maltreatment and reduced visual cortex volume in children and adolescents with reactive attachment disorder

Abstract

Reactive attachment disorder (RAD) is a severe social functioning disorder associated with early childhood maltreatment where the child displays emotionally withdrawn/inhibited behaviors toward caregivers. Brain regions develop at different rates and regions undergoing rapid change may be particularly vulnerable during these times to stressors or adverse experiences. The aim of this study was to investigate the effect of type and timing of childhood adversities on structural alterations in regional gray matter (GM) volume in maltreated children with RAD. High-resolution magnetic resonance imaging datasets were obtained for children and adolescents with RAD (n = 21; mean age = 12.76 years) and typically developing (TD) control subjects (n = 22; mean age = 12.95 years). Structural images were analyzed using a whole-brain voxel-based morphometry approach and the type and timing of maltreatment, which may be more strongly associated with structural alterations, was assessed using random forest regression with conditional inference trees. Our findings revealed that there is a potential sensitive period between 5 and 7 years of age for GM volume reduction of the left primary visual cortex (BA17) due to maltreatment. We also found that the number of types of maltreatment had the most significant effect on GM volume reduction and that the second most significant variable was exposure to neglect. The present study provides the first evidence showing that type and timing of maltreatment have an important role in inducing structural abnormalities in children and adolescents with RAD.

Keywords: Childhood maltreatment; Gray matter (GM) volume; Reactive attachment disorder (RAD); Sensitive period; Visual cortex; Voxel-based morphometry.

Fig. 1

Structural differences in regional gray matter (GM) volume between the typically developing (TD) and reactive attachment disorder (RAD) groups. The RAD group showed significantly reduced GM volume in the left primary visual cortex (BA 17) compared to the TD group (p = 0.038, FWE-corrected cluster level). Color scales represent t-values.

Fig. 2

(A) Maximal sensitivity by age of exposure (maximal importance of age of exposure, regardless of type) in RAD. Results of a random forest regression with conditional trees indicated the importance of exposure to early maltreatment from birth to 16 years of age on the GM eigenvariates for the left visual cortex. Importance is indicated by degradation in fit, as indicated by the increase in mean square error (MSE), following effective elimination of each age from the model by permutation. (B) Maximal sensitivity by type and number of maltreatments (maximal importance of type and number of maltreatments, regardless of age) in RAD. * p < 0.05; *** p < 0.001 (FDR-corrected for multiple comparisons).

Fig. 3

Sensitive periods of maltreatment exposure for each symptom of RAD. ANX: Anxiety, DEP: Depression, ANG: Anger, PTS: Post-traumatic stress, DIS: Dissociation, SC: Sexual concern. A dotted line represents a 0.01 p-value threshold FDR-corrected for multiple comparisons.