Transmission of traumatic childhood experiences across generations: mother-child interaction in traumatized mothers with borderline personality disorder

点击翻译按钮获取中文摘要

Childhood traumatic experiences (CT) are often transmitted across generations. An estimated 25% of abused children are likely to become abusive parents themselves. CT will here be defined as physical or sexual abuse experienced before the age of 17. The question arises which behavioral and neurobiological mechanisms underlie the transmission of abuse. Individuals differ in the way they react to CT. Two common reactions are borderline personality disorder (BPD) and depression (major depressive disorder, MDD). They represent externalizing (BPD) versus internalizing (MDD) styles of reaction to trauma. These variations in reactions to trauma may be critical for how CT are transmitted across generations and how transmission could be prevented.While some studies have investigated effects of maternal MDD on mother-child interaction, little attention has been paid to the effects of maternal BPD. Here we focus on a group that has not yet been studied: mothers who have responded to CT with BPD and their children of primary school age. They will be compared with traumatized mothers without BPD and with BPD mothers without CT. Our primary research question is: What are the specific effects of BPD psychopathology and of CT on mother-child interaction and how do these two factors interact?Data obtained in the proposed project will be compared with data from an ongoing BMBF project which is applying a similar test battery. In this BMBF project, we investigate mothers showing depressive reactions to CT, non-traumatized mothers with MDD and healthy mothers without CT. Our secondary research question is: Do effects of CT on mother-child interaction depend on the maternal reaction to trauma? To study the transgenerational transmission of CT we will combine behavioral observations of mother-child interaction using the emotional availability scale, functional magnetic resonance imaging (fMRI) and endocrinology. Particular emphasis will be placed on (1) maternal hostility and (2) child involvement with the mother during a free-play interaction and during a stress paradigm. Regarding the mother, we hypothesize: Both CT and BPD are associated with increased hostility, and the effects add up in mothers with both factors. Increased hostility is moderated by oxytocin and cortisol and is associated with amygdala hyper-responsiveness and hypo-active prefrontal emotion regulation networks during a maternal stress (anger) paradigm. In contrast, mothers responding to CT with MDD show decreased sensitivity. Regarding the child, we hypothesize: Both maternal CT and maternal BPD are associated with reduced child involvement with the mother, and the effects add up in children of mothers with both factors. In contrast, children of mothers responding to CT with MDD show over-involvement. This project contributes to our understanding of the transgenerational cycle of abuse and allows the identification of disorder-specific targets for intervention.