A study of veterans suffering from the posttraumatic stress disorder (PTSD) found that those undergoing mindfulness-based stress reduction therapy tended to have reduced symptoms after 9 weeks of treatment compared to a control group that underwent a mainstream therapy. Cortisol levels were increased in both groups, but less so in the mindfulness-based therapy group. The study was published in Mindfulness.

PTSD can develop after an individual has survived or witnessed an extremely adverse event, one that caused a psychological trauma. It is characterized by symptoms such as intrusive memories, flashbacks, nightmares, emotional distress, extreme sensitivity to potential threats, and constant scanning of the environment for threats. These individuals will also avoid situations that remind them of the trauma. It is estimated that around 6% of civilians and 8% to 17% of military personnel suffer from this disorder.

Existing treatments for PTSD are not always effective. Typically, mainstream treatments will be associated with reduction in symptoms in 50%-60% of patients. Due to this, there is intense scientific work to develop more effective treatments, but also to find ways to determine in advance which individuals will benefit from a certain treatment and which will not.

One promising approach to treating PTSD is mindfulness-based stress reduction therapy. Mindfulness is the practice of intentionally bringing one’s attention to the present moment with an attitude of open curiosity and non-judgment. It involves cultivating awareness of one’s thoughts, sensations, and surroundings, fostering a sense of clarity, presence, and acceptance. Studies have linked mindfulness resulting from the mindfulness-based stress reduction therapy to significant reductions in depression, anxiety, and PTSD symptoms.

Study author Itamar Shapira and his colleagues wanted to further examine the effects of mindfulness-based stress reduction therapy compared to present-centered group therapy, one of the mainstream approaches to psychotherapeutic treatment of PTSD patients. Present-centered group therapy is a form of therapy that emphasizes addressing current issues and challenges in a group setting, aiming to improve coping skills and overall well-being through discussions and support from both the therapist and group members.

Participants were 210 U.S. military veterans diagnosed with PTSD. Of these, 106 underwent the present-centered group therapy and 104 were assigned to the mindfulness-based stress reduction treatment. Prior to the study, participants agreed to remain on a stable regime of psychoactive medications if they were using such medications during the study. They also agreed to refrain from participating in other evidence-based psychotherapies during this time. Participants were recruited from two sites – Minneapolis and Tuscaloosa.

Participants underwent 8 weeks of therapy, either mindfulness-based stress reduction or present-centered group therapy, depending on the group they were assigned to. At the start of the study, in 3-week intervals during the treatments, and at weeks 9 and 16 since the start of the study, participants completed assessments of PTSD symptom severity, mindfulness, and the severity of depression symptoms. Researchers also analyzed blood samples of participants to assess levels of the hormone cortisol, and two indicators of immune system status (c-reactive protein and interleukin-6).

Results showed that, at the start of the study, participants planned for the mindfulness-based stress reduction treatment had more severe PTSD symptoms. In spite of that, after 9 weeks, participants that underwent mindfulness-based stress reduction treatment had significantly decreased PTSD symptoms compared to the present-centered therapy group. The former have also increased their mindfulness levels, while the latter group’s mindfulness levels were the same as they were at the beginning.


An increase in mindfulness was linked to a decrease in symptoms of PTSD and depression, and an increase in the levels of the hormone cortisol. Immune system markers (c-reactive protein and interleukin-6) did not differ between groups or between timepoints.

“Our study found that lower baseline cortisol levels were associated with greater self-reported PTSD severity which is consistent with previous findings that PTSD severity is related to depressed cortisol awakening response in combat veterans and associated with hypocortisolism and diurnal rhythm abnormalities. Our modelling found that increased mindfulness was associated with an increase in morning cortisol, perhaps indicating improved cortisol flexibility,” the study authors added.

The study makes a valuable contribution to the scientific knowledge about effects of PTSD treatments. It should, however, be noted that the study did not follow participants past week 16. Due to this, it remains unknown how symptoms changed after the study period. Additionally, all study participants were U.S. military veterans. Results on different groups might not be the same.

The study, “Biomarker Response to Mindfulness Intervention in Veterans Diagnosed with Post‑traumatic Stress Disorder”, was authored by Itamar Shapira, Joshua Richman, Thaddeus W. W. Pace, Kelvin O. Lim, Melissa A. Polusny, Mark B. Hamner, J. Douglas Bremner, Mercy N. Mumba, M. Lindsey Jacobs, Patricia Pilkinton, and Lori L. Davis.