Associations between Maternal Borderline Personality Disorder Symptoms, Parenting, and Mother-Child Cortisol Levels

Children of mothers with borderline personality disorder (BPD) are at heightened risk for developing mental health difficulties but the pathway through which this risk is conferred is unclear. Developmental psychopathology theories have highlighted parenting and stress physiology as potential mechanisms for the intergenerational transmission of mental health outcomes that may be particularly relevant to children of mothers with BPD. The aims of this dissertation were to 1) identify associations between maternal BPD symptoms and observed parenting behaviors and 2) examine whether positive parenting behaviors mitigated the risk of disrupted child stress physiology within the context of maternal BPD. To do this, two studies were conducted using both a clinical and community sample of mothers with BPD symptoms to examine both salivary cortisol levels and hair cortisol concentrations as measures of stress physiology.Across both studies, maternal BPD symptoms were not associated with displays of positive parenting behaviors. This may be a unique strength of mothers with BPD, as maternal psychopathology in other contexts (e.g., maternal depression) has been consistently associated with lower levels of positive parenting behaviors. Maternal BPD symptoms were associated with disrupted child salivary cortisol levels through its influence on maternal salivary cortisol levels. However, maternal BPD symptoms were not associated with mother-child hair cortisol concentrations which may be due to a lack of sensitivity in hair cortisol concentrations to psychosocial adversity, especially for children. In both studies, positive parenting behaviors were not associated with child stress physiology, which may be due to low power to detect effects as well as limited variability in parenting behaviors. Across both studies, the strongest predictor of child stress physiology was maternal stress physiology. These findings are contextualized within broader theoretical models of early adversity on child stress physiology, as well as a discussion comparing the use of salivary and hair cortisol collections as measures of stress physiology. As the field continues to develop approaches to reduce suffering and promote healthy child development in families of mothers with BPD, the role of parenting and dyadic stress physiology should continue to be explored as targets for intervention and prevention.2023-10-1