Adverse Childhood Experiences and Parenting Stress in Foster Families: Mentalizing as a Pathway to Strain

Adverse childhood experiences (ACEs) can compromise parents’ ability to form supportive and attuned parent-child relationships, and mentalizing may be a critical conduit linking ACEs to perceived relational strain, a core dimension of parenting stress. Foster parents may be especially vulnerable due to elevated ACE exposures and the demands of parenting children with complex needs in high-stakes caregiving contexts. Despite these risks, research examining how ACEs influence perceived relational strain through mentalizing remains limited in foster families. Data was obtained from a randomized controlled trial (RCT) of a psychoeducational mentalizing intervention for 89 foster parents. A mediation analysis tested mentalizing as an indirect influence on links between parental ACEs and perceived relational strain (as a key dimension of parenting stress). ACEs were associated with increased pre-mentalizing scores, reflecting a reduction in mentalizing capabilities (b = 0.098, p < .05), which in turn was associated with higher levels of perceived relational strain (b = 8.61, p < .001). Bootstrapping (with 5,000 samples) confirmed a statistically significant indirect effect (b = 0.84, 95% CI 0.06, 1.62, p = .034). The contributions of ACEs and mentalizing to perceived relational strain were asymmetrical; ACEs explained 5% of the variance in mentalizing (R² = 0.05), whereas ACEs and mentalizing together explained 31.6% of the variance in parenting stress (R² = 0.316). Sensitivity analyses supported the temporal ordering of variables through longitudinal design. This study highlights the importance of mentalizing capacity as a critical pathway linking ACEs to perceived relational strain in this sample of foster families. Adverse childhood experiences (ACEs) were associated with reduced mentalizing capacity and parenting stress among foster parents. Lower mentalizing capacity was strongly associated with higher perceived relational strain, a core dimension of parenting stress. Mentalizing mediated the association between foster parents’ ACEs and perceived relational strain. Mentalizing accounted for a substantial proportion of variance in parenting stress, suggesting a modifiable target for intervention.