Alterations in Brain and Immune Function Produced by Mindfulness Meditation
Davidson RJ, Kabat-Zinn J, Schumaker J, Rosenkranz M, Müller D, et al.;
Commented by , 25 Aug 2003
Background
Mindfulness-based stress reduction (MBSR) has demonstrated improvements in physical and mental health across a range of psychiatric and medical populations, yet the underlying biological processes remain elusive.
Purpose
Using a randomized controlled design, examine the effects of an 8-week MBSR program on brain and immune function in healthy employees.
Methods
41 right-handed employees of an American biotechnology corporation were randomly assigned to the meditation group (N=25; 19 female) and control group (N=16, 10 female); mean age of 36 years. The meditation training was modeled on the MBSR program of J.K.-Z. (1), consisting of weekly 2.5-3 hour classes and a silent 7-hour retreat during week 6. Subjects were also assigned home meditative practices.
For all subjects, brain electrical activity (EEG) was measured before (Time 1), immediately after (Time 2) and 4-months after (Time 3) the program. At each time point, subjects completed the Positive and Negative Affect Scale (PANAS) and the Spielberger State-Trait Anxiety Inventory (STAI).
Subjects were vaccinated with the influenza vaccine at 8 weeks. Blood samples were obtained at 3-5 and 8-9 weeks post-vaccination to examine antibody titers in response to the vaccine. Group X Time interaction (MANOVAs) and linear trends (ANOVAs) were tested (p < 0.05).
Results
There was a significant Group X Time interaction on trait anxiety (STAI) from Time 1-2; also a significant decrease in trait negative affect (PANAS) at Times 2 and 3 compared to Time 1, not observed in the control group.
Based on previous findings linking left-sided anterior activation with positive affect, 4 anterior electrode sites were specifically examined. Both Group X Time interaction and linear trends demonstrated significantly greater left-sided anterior activation. There were no group differences for any of the posterior sites.
The intervention group had a significantly greater rise in antibody titers to influenza vaccine. The magnitude of increase in left-sided anterior activation predicted the magnitude of antibody titer rise.
Discussion
Previous research has established an association between dispositional positive affect and left-sided anterior activation. Pre-clinical data also suggests prefrontal activation asymmetries are plastic and could be shaped by training.
This is the first study to support this plasticity model, whereby reductions in anxiety and increases in positive affect following MBSR were associated with increased left-sided activation.
Greater baseline anterior left-sided activation has been associated with enhanced immune function. Recent research has demonstrated the negative impact of antibody titers in response to influenza vaccine. Using this measure of immunity, the authors have set another precedent as the first group to demonstrate the effect of meditation on immune function.
Several limitations deserve brief mention. As the authors note, electrical brain activity is a rather crude measure of brain function. Future studies should involve more specific measures such as functional magnetic resonance imaging. The use of a healthy as opposed to a clinical sample also limits the generalizeability of the findings.
Notwithstanding these limitations, the study is an important contribution wading in at the frontier of psychoneuroimmunology. It lends further scientific support to meditation practice, which may be otherwise viewed as a “soft science”.
References
1. Kabat-Zinn J. Full catastrophe living: using the wisdom of your body and mind to face stress, pain and illness. New York: Delacorte; 1990.
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