Childhood adversity severity modulates the associations between adaptive psychological changes and amygdala volumetric changes in response to behavioral interventions.

Among young adult survivors of childhood adversity, an eight-week Mindfulness-Based Intervention (MBI) and a Stress Management Education (SME) program both led to increased mindfulness, reduced stress, and improved depression, anxiety, and somatization symptoms, with no significant difference between the two groups. Neither group showed greater changes in amygdala volume. Within the MBI group, the severity of childhood maltreatment mediated the link between mindfulness changes and right amygdala volume changes. Across both groups, childhood maltreatment moderated the effect of trait anxiety changes on left amygdala volume changes. The findings suggest that psychological-change-dependent amygdala volumetric changes are not unique to mindfulness training.

Study at a glance

Abstract

Adverse Childhood Experience (ACE) has been shown to have detrimental impact on amygdala structure. Prior research found that adaptive psychological changes after Mindfulness-Based Interventions (MBI) were associated with amygdala volumetric changes. The present study aims to further investigate whether such effects also occur among ACE survivors and whether the effects are unique to MBI. A total of 64 young adult childhood adversity survivors were randomized to an eight-week MBI or Stress Management Education (SME) as an active control condition. Anatomical MRI and questionnaires on mindfulness, stress and psychological health were collected at baseline and post-intervention. Due to subject dropout, the final sample included 39 subjects (MBI:20, SME:19). Both groups showed increased mindfulness levels, reduced stress, and improved psychological symptoms (depression, anxiety, and somatization), with no significant group by time interaction effect. There was no significant group difference on amygdala volumetric changes. Within the MBI group, childhood maltreatment severity was a significant mediator between changes of mindfulness levels and right amygdala volumetric changes. Across pooled sample of both groups, childhood maltreatment was a significant moderator for the effect of trait anxiety level changes on left amygdala volumetric changes. Modest sample size, relatively low retention rates, suboptimal monitoring of home practice. MBI did not demonstrate overall better clinical effects than SME. Psychological-change-dependent amygdala volumetric change was not specific to MBI. Childhood maltreatment severity modulated the relationships between adaptive psychological changes and amygdala volumetric changes.