Enhanced psychosocial well-being following participation in a mindfulness-based stress reduction program is associated with increased natural killer cell activity

Background: Mindfulness-based stress reduction (MBSR) programs have consistently been shown to enhance the psychosocial well-being of participants. Given the well-established association between psychosocial factors and immunologic functioning, it has been hypothesized that enhanced psychosocial well-being among MBSR participants would be associated with corresponding changes in markers of immune activity. Objectives: The objectives of this study were to examine changes in psychosocial and immunologic measures in a heterogeneous patient sample following participation in a MBSR program. Design: A single-group, pretest/post-test design was utilized. Setting: The intervention was conducted at an academic health center. Subjects: This pilot study involved 24 participants (aged 28-72 years). Inclusion criteria were as follows: ≥18 years of age, English-speaking, and no known autoimmune disorder. Intervention: The intervention was an 8-week MBSR program. Outcome measures: Distress and quality of life (QOL) measures included the Brief Symptom Inventory-18 and the Medical Outcomes Survey Short-Form Health Survey, respectively. Immunologic measures included natural killer (NK) cell cytolytic activity and C-reactive protein (CRP). Results: Patients completed psychosocial assessments and provided a blood sample at baseline (pre-MBSR) and within 2 weeks post-MBSR. Significant improvements in anxiety and overall distress as well as across multiple domains of QOL were observed from baseline to post-MBSR. Reductions in anxiety and overall distress were associated with reductions in CRP. Patients who reported improvement in overall mental well-being also showed increased NK cytolytic activity from pre- to post-MBSR, whereas patients who reported no improvement in mental well-being showed no change in NK cytolytic activity. Conclusions: Positive improvement in psychologic well-being following MBSR was associated with increased NK cytolytic activity and decreased levels of CRP.