Witnessing the victimization of a sibling in childhood is significantly associated with depression, even when other forms of family violence are statistically controlled (Teicher & Vitaliano, 2011). There is evidence suggesting that direct victimization and witnessing victimization are independently linked to depression (Johnson et al., 2002; Margolin et al., 2010; McKay et al., 2021). In addition, sex appears to influence sibling relationships, where older siblings are more likely to provide comfort in mixed sex dyads than in same-sex dyads (Whiteman et al., 2011). While outcomes associated with experiencing abuse directly have been studied, research into the sequelae of witnessing the abuse of a sibling is less developed.


We hypothesized that witnessing the abuse of a sibling in childhood accounts for unique variance in symptoms of depression in adulthood, after controlling for other forms of interpersonal trauma. We used the Conflict Tactics Scale, Parent-Child version (CTSPC; Straus et al., 1998) to measure physical and psychological childhood abuse perpetrated against a target sibling by mother and father figures. We assessed symptoms of depression with the Trauma Symptoms Inventory-2 (TSI-2; Briere, 1995). Our final sample consisted of 284, 18- to 56-year-old participants who resided in the United States. The sample included 80% women and 20% men.


We ran hierarchical multiple regression analyses to examine the relationship between witnessing the abuse of a sibling in childhood and depression symptoms in adulthood after other forms of trauma were controlled. Women who witnessed a brother's abuse reported significantly higher levels of depression than did participants in other sibling dyads, ΔF (1, 99) = 7.21, p = .008. For women, having witnessed their brother's physical abuse accounted for 18% of the variance in depression. In clinical practice, assessing and processing the experience of witnessing sibling abuse is critical when delivering trauma-informed care for adult women.