Day 5:
My capacity to notice small details has increased exponentially, for better and for worse. I am acutely aware of my body in a way I’ve never experienced. I can track with minute precision the moment a thought arises, the way it causes a ripple of physiological impact, the way that shapes the subsequent thoughts. When someone sneezes 20 feet away in the meditation hall, I can feel the impact of it slam into me, causing tingles and shivers. I am silent through it all, alone but deeply aware of others, wondering what their experiences are like.
What the Research Actually Shows
The scientific evidence for meditation is substantial but nuanced. It’s important to understand both what the research supports and where the limitations lie.
The Neurological Evidence
Brain imaging studies have shown that meditation can literally change the structure of your brain. This sounds impressive. But living also changes the structure of your brain because the brain adapts to inputs, habits, and experiences. So maybe it’s a better thing to say “meditation can literally change the structure of your brain in very specific and cool ways.” Research led by Sara Lazar at Harvard found that long-term meditators have thicker prefrontal cortex (associated with attention and sensory processing) and larger insula (linked to interoceptive awareness—your ability to sense internal bodily signals).¹
Perhaps more remarkably, an eight-week MBSR program produced measurable increases in gray matter density in areas associated with learning, memory, and emotional regulation, while decreasing gray matter in the amygdala, the brain’s alarm center.² These physical changes mirror participants subjective changes of greater self-awareness, more self-control, and more equanimity.
Psychological Benefits
Meta-analyses of meditation research show consistent, moderate benefits for several conditions:
- Anxiety: Large effect sizes (d=0.89) across multiple studies, meaning meditation can significantly reduce anxiety symptoms for many people.³
- Depression: Moderate effect sizes (d=0.59-0.69) for reducing depressive symptoms, with MBCT showing particular promise for preventing depression relapse.³ ⁴ (Using meditation for depression is a bit more complex, however. More on that later.)
- Stress: Moderate to large effects (d=0.74) for stress reduction in both clinical and non-clinical populations.⁵ This means that even without an official DSM diagnosis, an average person can expect meditation to help with the trials and tribulations of life.
- Chronic Pain: Significant reductions in pain intensity and improved quality of life, though the mechanisms may involve changing the relationship to pain rather than eliminating it.⁶
- Attention and Focus: Improvements in sustained attention, working memory, and cognitive flexibility, with benefits appearing after just a few weeks of practice.⁷
Physical Health Benefits
The research extends beyond psychology to physical health outcomes:
- Reduced blood pressure and cardiovascular risk
- Improved immune function
- Better sleep quality
- Reduced inflammation markers
- Potential benefits for chronic conditions like psoriasis and inflammatory bowel disease
Important Limitations
However, the research landscape has significant limitations that are often overlooked in popular discussions:
- Methodological Issues: Many studies suffer from small sample sizes, lack of proper control groups, and researcher bias. It’s difficult to create “placebo meditation,” so many studies compare meditation to wait-lists rather than active interventions.
- Publication Bias: Positive results are more likely to be published than null findings, potentially inflating the apparent benefits. But this isn’t unique to meditation research though. Rather, this is a fundamental problem with the scientific project as a whole, across disciplines from physics to chemistry to medicine to psychotherapy.
- Individual Variation: The research shows average effects, but individual responses vary tremendously. What works well for one person may be ineffective or even harmful for another. This is one of the guiding principles behind the therapeutic work and research that we do – understanding how to tailor treatment recommendations for specific people.
- Short-term Focus: Most studies examine effects over weeks or months. We know less about long-term outcomes or what happens when people stop practicing.
Next week: What Headspace Doesn’t Advertise – When Meditation is Harmful
References – Post 4
- Lazar, S. W., Kerr, C. E., Wasserman, R. H., Gray, J. R., Greve, D. N., Treadway, M. T., McGarvey, M., Quinn, B. T., Dusek, J. A., Benson, H., Rauch, S. L., Moore, C. I., & Fischl, B. (2005). Meditation experience is associated with increased cortical thickness. NeuroReport, 16(17), 1893-1897.
- Hölzel, B. K., Carmody, J., Vangel, M., Congleton, C., Yerramsetti, S. M., Gard, T., & Lazar, S. W. (2011). Mindfulness practice leads to increases in regional brain gray matter density. Psychiatry Research: Neuroimaging, 191(1), 36-43.
- Goldberg, S. B., Tucker, R. P., Greene, P. A., Davidson, R. J., Wampold, B. E., Kearney, D. J., & Simpson, T. L. (2018). Mindfulness-based interventions for psychiatric disorders: A systematic review and meta-analysis. Clinical Psychology Review, 59, 52-60.
- Kuyken, W., Warren, F. C., Taylor, R. S., Whalley, B., Crane, C., Bondolfi, G., Hayes, R., Huijbers, M., Ma, H., Schweizer, S., Segal, Z., Speckens, A., Teasdale, J. D., Van Heeringen, K., Williams, M., Byford, S., Byng, R., & Dalgleish, T. (2016). Efficacy of mindfulness-based cognitive therapy in prevention of depressive relapse. JAMA Psychiatry, 73(6), 565-574.
- Chiesa, A., & Serretti, A. (2009). Mindfulness-based stress reduction for stress management in healthy people: A review and meta-analysis. Journal of Alternative and Complementary Medicine, 15(5), 593-600.
- Goyal, M., Singh, S., Sibinga, E. M., Gould, N. F., Rowland-Seymour, A., Sharma, R., Berger, Z., Sleicher, D., Maron, D. D., Shihab, H. M., Ranasinghe, P. D., Linn, S., Saha, S., Bass, E. B., & Haythornthwaite, J. A. (2014). Meditation programs for psychological stress and well-being: A systematic review and meta-analysis. JAMA Internal Medicine, 174(3), 357-368.
- Brefczynski-Lewis, J. A., Lutz, A., Schaefer, H. S., Levinson, D. B., & Davidson, R. J. (2007). Neural correlates of attentional expertise in long-term meditation practitioners. Proceedings of the National Academy of Sciences, 104(27), 11483-11488.
