Determinants of sibling relationships in the context of mental disorders

Many studies have been conducted on sibling relationships to explore the well-being of siblings of persons with mental disorders. In this research project, two mediation models were tested. Model 1 examined whether a sibling's distress and the quality of the parent-typically developing sibling relationship would mediate the path between sibling-focused parentification and sibling relationships. Model 2 tested the same paths by comparing siblings of persons with mental disorders (n = 262) and siblings of typically developing persons (n = 303). From March to May 2021, 565 siblings of persons with and without mental disorders were asked to fill in an online survey. Aged 19 to 26 years, most of the siblings who participated in the study were older females. Cross-sectional results showed that the lower sibling-focused parentification was, the higher quality sibling relationships were, through the mediating role of lower distress and higher-quality parent-typically developing sibling relationships (Model 1). Siblings of persons with mental disorders reported low-quality sibling relationships (Model 2). Females and young siblings showed high distress. The findings of this study could become instrumental in promoting high-quality sibling relationships and best practices.