Can meditation change the brain?

What do well-controlled studies say about how meditation helps?

The key question for any study is “compared with what?” Many meditation studies compare meditators with people on a waiting list, who get nothing. Then it is hard to tell whether meditation helped, or simply the time, attention and hope that come with any class. The 2014 review in JAMA Internal Medicine, led by Madhav Goyal of Johns Hopkins University, dealt with this by including only trials with an “active control,” another activity that took the same time and attention. From 18,753 citations, the team kept 47 trials with 3,515 adults who had a range of health conditions.

Mindfulness programs showed moderate evidence of easing anxiety, depression and pain. The effects were small to moderate, and some were still there three to six months later. The evidence was weaker for stress and quality of life. For positive mood, attention, sleep, eating, substance use and weight, the evidence showed no effect or was too thin to judge. And the review found no evidence that meditation programs did better than drugs, exercise or other behavioral therapies.

Other reviews are more upbeat. The U.S. National Center for Complementary and Integrative Health (NCCIH) describes a 2018 analysis of 142 groups of patients with diagnosed conditions such as anxiety or depression, more than 12,000 people in all. For anxiety and depression, mindfulness approaches beat no treatment and worked as well as established treatments such as cognitive behavioral therapy and antidepressant medicines. The same page notes a 2021 analysis of treatment for anxiety disorders, in which the few studies that followed people for more than two months found no long-term effects.

Some strong warnings come from inside the field. In 2018, 15 researchers published a review called “Mind the Hype.” They warned that misinformation and poor methods could leave people “harmed, misled, and disappointed.” They cited an estimate that only 9% of research on mindfulness programs had reached the stage of testing them against an active control. One author had co-written the 2011 brain study described below.

Does meditation change the brain’s structure?

Some change would not be surprising. Research shows the brain changing with experience in sensory, motor and thinking skills. The question is how much meditation changes it.

In a widely referenced 2011 study, a team at Massachusetts General Hospital and Harvard Medical School scanned 16 healthy people before and after the eight-week Mindfulness-Based Stress Reduction course, known as MBSR, and compared them with 17 people on a waiting list. They reported increases in gray matter concentration, a measure of brain tissue, in the left hippocampus and in areas linked to learning, memory, handling emotions and taking another person’s point of view.

In 2022, a team at the University of Wisconsin–Madison ran a bigger test. They combined two randomized trials with 218 people who had no prior training in meditation. Each person was assigned by chance to MBSR, to a matched health program, or to a waiting list. The researchers failed to replicate the earlier findings and found no evidence that MBSR changed brain structure compared with either control group. In the same study groups, the course did change how some brain areas responded and connected, and self-reported mindfulness rose. But the matched health program raised self-reported mindfulness about as much. The authors add a caution: their volunteers were unusually healthy, while earlier studies drew people seeking stress relief, who may have had more room to improve.

Longer training looks more promising. A 2017 study followed 332 adults. Most did daily mental exercises and weekly group sessions, in three-month modules over up to nine months; a comparison group did no training. Training focused on present-moment attention, which resembled mindfulness, mostly thickened the cortex, the brain’s outer layer, in regions at the front. A 2014 analysis of 21 imaging studies of about 300 meditators found eight brain regions that differed consistently, with an overall “medium” effect size. Its authors, though, called publication bias and the limits of the studies’ methods “strong concerns.”

What is the strongest objection to brain-scan claims?

The “Mind the Hype” authors list several traps that can make brain studies look stronger than they are.

• Brain pictures hide many steps. A brain image is the end of a long chain of biological and computer steps, and it is often a group average, not a picture of one person.
• A snapshot cannot show cause. Many studies compare long-time meditators with non-meditators at one moment. The Wisconsin team notes that such people may have differed from the start, and may live differently.
• Stillness can fool the scanner. If non-meditators fidget or breathe faster in the machine, the scans can show false differences.
• Small groups give shaky results. The review warns about small samples.

The same authors add that differences seen across many studies are less likely to be mere artifacts. There is also a deeper point. A change in the brain does not settle whether the mind is only the brain. That question is still open: see Is the mind just the brain? If you have heard that quantum physics explains the mind, see What does quantum physics really say about consciousness and healing?

Can meditation cause harm?

Meditation is usually considered to have few risks, but few studies have checked. A 2020 review of 83 studies with 6,703 participants found that 55 of the studies reported at least one negative effect. Overall, 8.3% of participants had one. The rate was 3.7% in experimental studies and 33.2% in observational ones. The most common problems were anxiety, depression and what the review calls “cognitive anomalies,” or unusual changes in thinking. These can occur in people with no past mental-health problems. NCCIH adds that this rate is similar to the one reported for psychological therapies.

The figure from experiments may miss harms: the “Mind the Hype” authors note that fewer than 25% of meditation trials actively ask about them. They also note that meditation-related difficulties are discussed in many traditional, largely Buddhist, meditation guides.

NCCIH’s advice is plain: do not use meditation to replace medical care or to put off seeing a health care provider, and ask about your instructor’s training. If meditation stirs up distress that does not pass, tell a doctor or someone you trust. Our page If a question is personal right now is a place to start.

Where do contemplative traditions and scientists meet?

NCCIH notes that meditation goes back thousands of years and that many techniques began in Eastern traditions. The word mindfulness has its historical roots in Buddhism. A central text is the Satipatthana Sutta, number 10 in the Middle Discourses. Its translator, Bhikkhu Sujato, calls it and a longer version the most influential texts for modern Theravada meditation. It teaches a meditator to sit down, set the body straight and be mindful of the breath, and to observe the body, feelings, the mind and principles. It says these practices are meant “to get past sorrow and crying, to make an end of pain and sadness,” and to realize extinguishment, nibbāna in the Pali language. In the translator’s notes, mindfulness is the seventh factor of the Noble Eightfold Path. In that tradition, stress relief is not the whole point.

MBSR was introduced in the late 1970s as a complementary therapy for people with medical illness. From 1987, the Mind and Life Institute helped bring the Dalai Lama and scientists together in regular dialogues. People of faith and skeptics can agree on several things:

• Attention can be trained. In the nine-month study, brain changes tracked improvements in attention in the same people.
• Practice can be hard. Traditional guides and modern safety reviews both warn about difficult experiences.
• Claims should match the evidence. Overselling meditation can mislead the very people it could help.
• Some goals lie beyond a scanner. Whether meditation leads to awakening is a question for practice and faith, and we label it Beyond science.

On awe, a feeling many people call spiritual whether they are religious or not, see Why do we feel awe under the night sky?

How can you check a meditation claim yourself?

• Ask “compared with what?” A study against a matched activity tells you more than one against a waiting list.
• Count the people. The 2011 brain study had 16 people in its course; the 2022 test had 218 across its three groups.
• Check the design. Did the same people get scanned before and after training, or were two different groups compared once?
• Look for harms. Did the study ask about bad effects, or only wait for people to mention them?
• Read the review yourself. The authors’ manuscript of the Goyal review is free to read on PubMed Central, and NCCIH has a plain-language page.

The answer stays the same after all this detail. Meditation can modestly ease anxiety, depression and pain. It may change brain structure with longer practice, but how much is still debated, and a short course may not change it at all.