Perceptions of Women With Comorbid PTSD and Substance Use Disorder on Mechanisms Underlying Mindfulness-Based Interventions.

Women with comorbid posttraumatic stress disorder (PTSD) and substance use disorder (SUD) demonstrate the greatest psychiatric severity when entering mental health treatment, and poorest rates of treatment completion and relapse compared to those with either disorder alone. Mindfulness-based interventions (MBIs) for women with comorbid PTSD-SUD may be an effective treatment approach as it targets mechanisms underlying self-medication of trauma-related symptoms via substance use. Little is known, however, of the benefits of MBIs for this population. Thus, the purpose of this study was to qualitatively elucidate mechanisms of action in a pilot MBI adapted for women with comorbid SUD and PTSD, with the goal of identifying the most salient aspects of MBIs that target self-medication of PTSD symptoms via substance use. Following completion of a trauma-integrated MBI, women (N = 39) diagnosed with PTSD-SUD were invited to attend one of ten, 60-minute, audio-recorded focus groups. A semistructured interview protocol was utilized to investigate how participants perceived the utility of MBIs in mitigating PTSD and SUD symptoms over the course of the intervention. Conventional content analysis guided qualitative analysis and reporting. Participants described four mechanisms through which they experienced MBIs attenuating the relationship between PTSD and SUD: increased attention to trauma- and substance-related triggers occurring in the present moment; greater cultivation of nonjudgmental acceptance to aversive experiences; development of self-compassionate attitudes toward suffering; and increased tolerance to aversive experiences. Building upon these mechanisms of action, we propose a moderated mediation model, in which increased present-moment awareness, nonjudgmental attitudes toward distress, and self-compassion reduce impulsivity and negative affect, which then increases tolerance for aversive experiences, thereby attenuating the relationship between PTSD and SUD symptoms. Interventions targeting the four proposed mechanisms may be considered when treating women diagnosed with comorbid PTSD-SUD.