Mindfulness mental training, most frequently in the form of Mindfulness-Based Stress Reduction (MBSR, as developed by John Kabat-Zinn), has been shown to protect or enhance cognition, well-being and physical health in multiple clinical populations and in healthy adults. Two decades of research have shown that MBSR and MBSR-based interventions create new habits in the brain subserved by organic, structural changes. Such interventions have been shown to protect cognitive function in pre-deployment marines and incarcerated juveniles; reduce relapse in major depressive disorder; enhance immune function in HIV+ males; reduce PTSD severity in veterans; enhance job performance in inner-city teachers; improve cognitive function and pro-social skills in children; increase professionalism and decrease burnout in PCPs; improve work satisfaction and engagement in numerous populations of health care workers; and diminish psychological stress in soldiers, physicians and professional athletes.