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: > or =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.