Program for Alleviating and Resolving Trauma and Stress 2

This pilot RCT will test the preliminary efficacy of an intensive group model of Internal Family Systems (IFS) called the Program for Alleviating and Resolving Trauma and Stress (PARTS) compared with a Nature-Based Stress Reduction for Trauma Survivors (NBSR-T) attention placebo control group at reducing PTSD symptom severity measured by Clinician-Administered PTSD Scale (CAPS-5). In addition, the effects of the interventions on self-reported PTSD symptoms, disassociation, and disturbances of self-organization (DSO), as well as mechanisms of emotion regulation, decentering and self-compassion will be secondary outcomes.