Moderators of Treatment Efficacy in a Randomized Controlled Trial of Trauma-Sensitive Yoga as an Adjunctive Treatment for Posttraumatic Stress Disorder

Objective: This study is a follow-up to van der Kolk et al. (2014), a trial conducted through the Trauma Center at Justice Resource Institute, which demonstrated treatment efficacy and remains the only randomized controlled trial of trauma-sensitive yoga. The present process study extends the outcomes study by examining treatment moderators of the original trial. Method: Sixty-four women with childhood interpersonal trauma histories and posttraumatic stress disorder participated in the interventions: Trauma Center Trauma-Sensitive Yoga (TCTSY) versus active control (women's health education). Analyses explored if adult-onset interpersonal trauma and baseline psychological measures (clinician-rated and self-reported PTSD, dissociation, depression, psychological functioning) moderated PTSD changes. Results: Three of six measures had small effects in moderating the relationship between adult-onset interpersonal trauma and TCTSY efficacy, in which TCTSY was most efficacious for those with fewer adult-onset interpersonal traumas. Within this subgroup, various levels of all baseline measures except depression indicated that TCTSY was more effective in reducing PTSD than the active control condition. Conclusions: By delineating client characteristics most associated with PTSD improvements, practitioners may best target yoga interventions to increase effectiveness.