Veterans with PTSD who participated in a mindfulness-based stress reduction program experienced greater decrease in symptom severity, compared with those who participated in present-centered group therapy, according to a randomized, controlled trial. However, the magnitude of the average improvement was considered modest.
“The quality of scientific evidence supporting the efficacy of mindfulness-based interventions has recently been criticized,” researchers led by Melissa A. Polusny, Ph.D., reported on Aug. 4. “This study improves on shortcomings of previous trials by comparing mindfulness-based stress reduction with an active, credible control condition, taking steps to ensure treatment fidelity, and using both patient-reported and blinded clinician ratings of PTSD outcomes.”
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From March 2012 to December 2013, Dr. Polusny of the Minneapolis VA Medical Center and her associates randomly assigned 116 veterans with PTSD to one of two treatment groups: 58 to mindfulness-based stress reduction therapy (MBSR) and 58 to patient-centered group therapy (PCT), each delivered in nine weekly group sessions (JAMA. 2015 Aug 4;314(5):456-65.). The MBSR sessions focused on teaching patients to attend to their thoughts, emotions, and sensations with an attitude of nonjudgment, kindness, and curiosity. The PCT sessions focused on teaching patients to tap into their existing skills and strengths to cope effectively with current stressors that might be exacerbated by PTSD symptoms.
The primary outcome was change in PTSD severity over time as measured by the PTSD Checklist (PCL) at weeks 3, 6, 9, and 17 (the 2-month follow-up). Possible PCL scores ranged from 17 to 85, with higher scores indicating more severe PTSD symptoms. Secondary outcomes included diagnosis and symptom severity of PTSD based on the Clinician-Administered PTSD Scale (CAPS) at baseline, week 9, and week 17, as well as improvements in depressive symptoms, quality of life, and mindfulness.
The mean age of study participants was 59 years, and 84% were white. Between baseline and week 9, PCL scores among patients in the MBSR group improved from 63.6 to 55.7, while scores among patients in the PCT group improved from 58.8 to 55.8, which translated into a between-group difference of 4.95 (P = .002). Between baseline and week 17, PCL scores among patients in the MBSR group improved from 63.6 to 54.4, while scores among patients in the PCT group improved from 58.8 to 56, which translated into a between-group difference of 6.44 (P less than .001).
As for secondary outcomes, patients in the MBSR group were more likely to demonstrate significant improvement in self-reported PTSD symptom severity at week 17, compared with their counterparts in the PCT group (48.9% vs. 28.1%, respectively, for a between-group difference of 20.9%; P = .03). However, they were no more likely to have loss of PTSD diagnosis (53.3% vs. 47.3%, respectively, for a between-group difference of 6%; P = .55).
Using a 10-point or greater reduction on the CAPS as a benchmark, the researchers found that both groups were similar in the percentage of participants showing clinically significant improvement in interview-rated PTSD symptom severity at 2-month follow-up (66.7% among patients in the MBSR group vs. 54.5% in the PCT group, for a between-group difference of 12.1%; P = .22). In addition, similar percentages of participants reported clinically significant improvement in depressive symptoms on the PHQ-9 (27.7% among patients in the MBSR group, vs. 22.8% in the PCT group, for a between-group difference of 4.9%; P = .57).
“Findings from the present study suggest that veterans who received mindfulness-based stress reduction therapy reported significant improvement in mindfulness skills after treatment, while there appeared to be little change in mindfulness skills reported by veterans who received present-centered group therapy,” the researchers wrote. “Moreover, findings suggest that greater reductions in PTSD symptom severity were associated with changes in mindfulness over the course of treatment. Improvements in quality of life made during treatment appeared to be maintained through the 2-month follow-up for participants receiving mindfulness-based stress reduction therapy, but reports of quality of life appeared to return to baseline levels for present-centered group therapy participants during this same follow-up period. Taken together, these findings suggest that mindfulness-based stress reduction may provide veterans with internal tools for promoting self-management of PTSD symptoms and quality of life.”
They acknowledged certain limitations of the study, including the fact that even though groups were structurally equivalent in number of weekly sessions, “therapist training and qualifications, and group format, present-centered group therapy may not have fully accounted for all nonspecific factors present in mindfulness-based stress reduction (e.g., therapist expectations) and was unequal in duration of sessions.”
The study was supported by the Minneapolis VA Health Care System and a grant from the Department of Veterans Affairs. The researchers reported having no financial disclosures.