Mindfulness-Based Stretching and Deep Breathing Exercises Normalize Serum Cortisol Levels and Reverse Symptoms of PTSD: A Prospective Randomized-Controlled Trial

Context: Cortisol, the human glucocorticoid, plays a key role in the pathophysiology of posttraumatic stress disorder (PTSD). It is known that individuals with chronic PTSD suffer from low basal cortisol levels. Endogenic normalization of basal cortisol concentration through exercise may have a therapeutic effect on treating PTSD symptoms, yet little is known about the association between exercise-induced endogenic increase of cortisol and PTSD symptom reduction. Objective: To identify whether mindfulness-based stretching and deep breathing exercise (MBX) increases basal cortisol levels, examine if MBX reduces PTSD symptom severity, and evaluate MBX as a complementary intervention for PTSD. Design: Prospective, randomized, controlled. Setting: University of New Mexico Hospital. Participants: 29 nurses with PTSD symptoms, ages 45-53, with 28 female. Intervention: 8-week bi-weekly 60-minute MBX sessions. Main Outcome Measures: Serum cortisol and PTSD Checklist-Civilian version (PCL-C) at weeks 0, 4, 8, 12, and 16. Results: Twenty-eight participants completed the study procedures. In EX group, serum cortisol levels increased significantly from 9.6±4.1 μg/dl at baseline to 14.6±5.7 μg/dl at week 8 (p=0.0039); PTSD symptom severity decreased significantly from PCL-C scores of 43.1±11.2 at baseline to 24±3.3 at week 8 (p=0.0002); and the effects were maintained at follow-up at week 16 with cortisol concentration of 14.0±3.9 μg/dl (p= 0.5706) and PCL-C scores of 25.0±5.1 (p=0.8013). Conclusions: The results indicate a strong relationship between changes in cortisol levels and changes in PTSD symptom severity. This study provides preliminary evidence that programs aimed at reducing symptom severity in individuals with chronic PTSD should consider a mind-body intervention. To our knowledge, this is the first randomized controlled trial to assess the therapeutic benefits of MBX in individuals with PTSD symptoms using both biomarkers and PCL-C scores measuring the long-term effects of cortisol changes