From Somatic Experiencing to Felt Safety: Assessing the effects of a body-oriented intervention in adults with various degrees of child maltreatment

Child maltreatment (CM) has been linked to diminished psychological safety and a sense of disrupted body boundaries – factors that can contribute to impaired social functioning. To date, evidence-based interventions to increase psychological safety and to diminish body boundary disruptions are lacking. As a first step to close this gap, we conducted two studies in which adults with various levels of CM were randomized to either a brief (60min) body-oriented intervention, based on Somatic Experiencing (SE) or to a control condition (group receiving information on trauma-related symptoms and on the SE intervention). Study I included participants with a lack of psychological safety (n=89), whereas Study II included individuals with a sense of disrupted body boundaries (n=55). Next to assessing changes in psychological safety (Study I), we explored changes in heart rate (HR) and heart rate variability (HRV) and disrupted body boundaries (Study II) from pre- to post-session. Moreover, we assessed whether an SE session, in line with proposed mechanisms of action, increases interoceptive awareness (Study II) and explored variables such as severity of CM that might moderate the effect of SE (both studies). Results showed a significant increase in psychological safety (d = -.95, p<.001) and a significant reduction in disrupted body boundaries (d = 1.13, p < .001) in the SE group but not in controls. HR decreased and HRV increased across groups (Study I), while interoceptive awareness increased from pre-to post only in the SE-group (Study II). Significant SE group-specific changes were also observed for different types of positive affect (especially safe/content and relaxed affective states), social connectedness and negative affect (Study I). Notably, the effects of SE on psychological safety, a sense of disrupted body boundaries, and interoception were stronger in individuals with greater CM severity and fewer positivechildhood memories. Overall, the results provide evidence for SE to facilitate momentary states of psychological safety, positive affective states of safety and relaxation, and show that a brief, SE-based intervention can improve social connectedness in adults with different levels of CM. More research is needed to explore longer-lasting positive effects of SE, including effects on social functioning.