Abstract
Empirical understanding of the effects of mindfulness-based interventions for post-traumatic stress disorder (PTSD) across different racial groups remains limited. This secondary analysis of a randomised controlled trial examined racial differences in trauma-related outcomes among U.S. frontline nurses traumatised by the COVID-19 pandemic. Participants (N = 56) were randomly assigned to either the MABSA intervention (Mindfulness and Acceptance-Based Smartphone App), a mindfulness app grounded in Acceptance and Commitment Therapy, or a wait-list control group. Outcomes included PTSD symptoms, experiential avoidance, rumination, mindfulness, and resilience. The intervention significantly reduced PTSD symptoms, experiential avoidance, and rumination for both Black and White participants compared to controls. A significant interaction effect was found for experiential avoidance, with Black participants showing greater improvement than their White counterparts. Across groups and time points, Black participants also consistently reported higher levels of rumination and mindfulness. These findings suggest that there may be differences in how individuals from different racial groups respond to mindfulness-based interventions, highlighting the importance of developing culturally informed PTSD treatments.