The role of reduced sense of isolation in group-format PTSD treatment.

With increasing application of group-based interventions for PTSD, more research is needed on what might contribute to the therapeutic effects of group-based interventions. This study conducted secondary analyses with data from a previous randomized controlled trial, which compared two manualized 16-week videoconferencing PTSD treatments in a hybrid format with 16 group sessions and 8 individual sessions. One treatment arm focused on cultivating inner compassion and understanding internal conflicts through a contemplative Internal Family Systems (IFS) approach, while the other treatment arm focused on watching nature videos and discussing nature's potential for stress reduction. The original RCT showed comparable effects on PTSD symptom reduction. Therefore, we conducted secondary analysis to elucidate whether both two group-based interventions, despite very different curriculum content, might have induced "reduced sense of isolation", which might be a shared therapeutic element in both treatment arms. Findings from Linear Mixed Effects model analysis and Variance Decomposition Analyses (VDA) showed significant reduction of sense of isolation at the end of both interventions, which was one of the major contributors to reduction of PTSD symptoms. Path analyses showed similarities between the two group-based treatment arms in which reduced sense of isolation was associated with improvements in self-judgment and emotion regulation, all of which contributed to PTSD symptom reduction. These findings may inspire and inform future PTSD treatment development to place more emphasis on reducing patients' sense of isolation.