Transcendental Meditation research

A comparison of the effect of various meditation techniques on systolic blood pressure, though according to the source, it wasn't possible to make strong inferences on which is the best intervention due to a lack of statistical power.

There has been ongoing research on Transcendental Meditation since the first studies examining TM were conducted at the UCLA and Harvard University were published in Science and the American Journal of Physiology in 1970 and 1971. Research reviews and medical textbooks say that the Transcendental Meditation technique (TM) is the most studied form of meditation, and that it has specific effects on human physiology. These reviews and textbooks differ with regard to their assessment of research quality and on the results of practicing TM. {{citation}}: Empty citation (help) Research reviews say that more research is needed to firmly establish the effects on mental and physical health. {{citation}}: Empty citation (help)

Independently done systematic reviews have not found health benefits for TM beyond relaxation or health education. It is difficult to determine definitive effects of "meditation practices in healthcare" as the quality of research has design limitations and a lack of methodological rigor. Part of this difficulty is due to the fact that studies have the potential for bias because of a connection of researchers to the TM organization, and on subjects with a favorable opinion of TM.

The research has included studies on physiological changes during meditation, clinical applications, cognitive effects, mental health, addiction, and rehabilitation. Beginning in the 1990s, a focus of research has been the effects of Transcendental Meditation on cardiovascular disease, with over $20 million in funding from the National Institutes of Health. Medical journals that have published the research include Archives of Internal Medicine (published by the American Medical Association) and Hypertension (published by the American Heart Association).

Health outcomes

In a 2007 government report, a meta-analysis of five studies on the effects of TM on hypertensive patients found that the effects were no greater than health education regarding blood pressure. Subgroup analyses of two or three of these five studies found no greater effect on body weight, heart rate, stress, anger, self-efficacy, cholesterol, dietary intake, or level of physical activity. However, a meta-analysis of the two high-quality studies that also compared TM to progressive muscle relaxation found that TM produced a greater reduction in blood pressure. The report also analyzed studies that compared TM to no treatment. In these studies, although TM did not produce significantly greater benefits on blood pressure, it did produce improvement in cholesterol levels and verbal creativity. In studies that compared TM to a wait-listed control group, TM resulted in greater reduction in blood pressure. The report's assessment of before-and-after studies on patients with essential hypertension found a reduction in blood pressure after practicing TM. The review concludes that firm conclusions regarding health effects cannot be drawn due to the poor quality of the research, though TM researchers said an inappropriate method of quality assessment was used.

A 2007 medical textbook on heart disease said that "TM has been shown to not only improve blood pressure but also the insulin resistance components of metabolic syndrome and cardiac autonomic nervous system tone." A 2007 review said that data from two studies found reduced mortality from all causes over a mean period of 8 years in subjects practicing Transcendental Meditation compared to controls. The review said that this finding is consistent with the research that found improved blood pressure, insulin resistance, and cardiac autonomic-nervous-system tone in subjects with cardiovascular disease. The review concluded that psychosocial interventions are effective in alleviating distress in cardiovascular patients but that further research is needed to firmly establish that these interventions can affect disease processes, morbidity, and mortality. Research also suggests that Transcendental Meditation may reduce atherosclerosis.

A 2008 meta-analysis of nine studies found a 4.7 mmHg systolic blood pressure and 3.2 mmHg diastolic blood pressure decrease in those who practiced TM compared to control groups that included health education. Three of the studies were assessed as good quality, three as acceptable, and three suboptimal. The review and its primary author were partially funded by Howard Settle, a proponent of TM. A 2007 meta-analysis by researchers at Maharishi University of Management and the University of Kentucky found that TM lowers blood pressure. The results differed from the 2007 government report mentioned above because the authors removed overlapping studies, corrected data collection errors, and included studies outside the scope of that report.

Research reviews published in 2009 and 2010 reported on several randomized controlled trials on Transcendental Meditation that found an improvement in blood pressure and cardiovascular function compared to health education. In addition, they reported on a randomized controlled trial on psychosocial and behavioral outcomes that compared TM to health education and found that the TM group had decreased absentee periods, rule infractions, and suspension days, but found no difference in the TM and control groups in regard to tardiness, lifestyle, or stress. The 2010 review concluded that "Studies of TM’s effect in youth on cardiovascular risk, cognition, affect, and behavior are promising, but larger, more definitive comparative effectiveness research is needed." The 2009 review said that because of limitations of the research, larger-scale and more demographically diverse studies need to be done to clarify treatment efficacy."

Mental function

A 2010 review by the Cochrane collaboration was unable to draw any conclusions regarding the effectiveness of meditation therapy (including TM ) for ADHD due to the lack of suitable evidence. A 2006 review by the Cochrane collabortion found that there was insufficient evidence to draw conclusions regarding the effectiveness of meditation for anxiety disorders. The review found that, as of 2006, two randomized controlled trials had been done on this topic, one of which was on TM, and concluded that meditation is equivalent to relaxation therapy in reducing anxiety. A meta-analysis of over 100 studies found that relaxation techniques reduce trait anxiety and that Transcendental Meditation had a larger effect size than other relaxation techniques.

Three studies published in 2001 in the scholarly journal Intelligence that were originally conducted by a Maharishi University of Management doctoral student in 1995 found that TM reduced anxiety compared to simple rest, contemplative meditation, and no treatment. His randomized controlled trial involving 154 high school students in China found that TM reduced anxiety compared to a control group that simply lay down to rest or sleep. He replicated that finding in two subsequent randomized controlled trials involving Chinese and Taiwanese students using contemplative meditation and no-treatment control groups. The three studies, characterized by Shauna L. Shapiro and Roger Walsh in a 2003 research review as being "well-designed studies", also found that TM improves cognitive performance, including increased practical intelligence, creativity, and speed of information processing.

A 2003 review by Peter Canter and Edzard Ernst concluded that evidence does not support a specific or cumulative effect from TM on cognitive function. The review did find positive results in studies that recruited people with favorable opinions of TM, and used passive control procedures. Edzard Ernst, professor of complementary medicine at the Peninsula Medical School in Exeter, was quoted in The Guardian newspaper as saying that "there is no good evidence that TM has positive effects on children. The data that exist are all deeply flawed."

Criminal rehabilitation, addiction

Transcendental Meditation has been used in correctional settings, and research has shown a reduction in negative psychological states and recidivism — that is, returning to criminal behavior after being released from prison. According to a 2010 research review, studies involving hundreds of prisoners at San Quentin and Folsom State Prisons in California and Walpole State Prison in Massachusetts found that recidivism rates were reduced by as much as 47%. Overall, the TM prisoners at Folsom were 43% less likely to return to prison compared to control groups. The study at Folsom also looked at anxiety measures and found a sharp reduction compared to controls. The review said that meditation studies may be subject to researcher bias and self-selection bias, but concluded that policy makers and prison officials may want to implement meditation programs in prisons.

A 2009 review looked at the effect of TM on addiction and noted that while many studies exist, they were conducted by researchers affiliated with Transcendental Meditation and were not randomized controlled trials. Thus the evidence for treating addictive disorders is speculative and inconsistent. It said that while the quasi-religious aspects and cost may deter people, the simplicity of the technique, the physiological changes it induces, and the apparent effectiveness in nonpsychiatric settings merit further study and that "the theoretical basis for meditation’s role in addressing substance use disorders is compelling" based on the physiological mechanisms that have been found. According to the Cambridge Textbook of Effective Treatments in Psychiatry, a randomized controlled trial that included the use of Transcendental Meditation in treating alcoholism found that TM and biofeedback increased abstinence in alcoholics. The textbook concluded that there is not yet sufficient evidence for use as treatment but that meditation can help alcoholic patients in a variety of ways.

Effects on the brain

Transcendental Meditation has been found to produce specific types of brain waves as measured by electroencephalography (EEG). Studies have found that, compared to a baseline, during meditation there is an increase in alpha amplitude followed by a slowing of the alpha frequency and the spread of this to the frontal cortex. Alpha brain waves are classically viewed as reflecting a relaxed brain. When compared to control groups using a different relaxation technique, the increase in alpha is similar and integrated alpha amplitude may even decrease compared to a baseline of eyes-closed rest.

Transcendental Meditation also produces alpha coherence, that is, large-scale integration of frequencies in different parts of the brain. This pattern is also sometimes seen while a subject is actively focusing his or her attention on an object or holding some information in mind. These brain patterns generally suggest a decrease in mental activity and are associated with a relaxed state. According to the Cambridge Handbook of Consciousness, TM promotional material has said that this coherence represents a more orderly state of the brain and one that is unique to TM. The Cambridge Handbook says that these claims may be overstated or premature. "Because alpha rhythms are ubiquitous and functionally non-specific, the claim that alpha oscillations and alpha coherence are desirable or are linked to an original and higher state of consciousness seem quite premature" and "alpha frequencies frequently produce spontaneously moderate to large coherence (0.3–0.8 over large inter-electrode distance.) The alpha coherence values reported in TM studies, as a trait in the baseline or during meditation, belong to this same range. Thus a global increase of alpha power and alpha coherence might not reflect a more 'ordered' or 'integrated' experience, as frequently claimed in TM literature, but rather a relaxed, inactive mental state."

EEG studies have shown an increase in theta waves and a dominant pattern of alpha waves in the frontal and occipital lobes. With long-term practice these changes seen in meditation carry over into activity. These changes may enhance brain integration and reduce emotional reactivity. According to a review by Lansky and St Louis, EEG measurements that show neuronal hypersynchrony are similar to those found in epilepsy, leading to concerns about the potential risk of kindling of epilepsy from repetitive Transcendental Meditation. But the authors say clinical studies have found meditation to be a possible antiepileptic therapy. They say that more research is needed "to establish the safety of this technique and its potential efficacy for seizure reduction and improvement of quality of life."

A brain imaging study on practitioners of Transcendental Meditation conducted by researchers affiliated with Maharishi University and the University of California at Irvine showed that TM decreases activity in the thalamus, prefrontal cortex, and anterior cingulate cortex in response to pain. The tests, which used functional magnetic resonance imagine (fMRI) found approximately a 50% reduction in these pain-processing regions of the brain compared to a control group. The results suggest that, while it does not reduce pain, TM does reduce the emotional distress associated with the experience of pain, resulting in greater tolerance.

Effects on the physiology

TM has been found to produce a set of characteristic responses such as reduced respiration, decreased breath volume, decreased lactate and cortisol (hormones associated with stress), increased basal skin resistance, and slowed heartbeat. The mechanism for the effects of TM has been explained by proponents as being due to greater order in the physiology, decreased stress, and growth of creative intelligence.

In their 1985 book on religion, Bainbridge and Stark say that subsequent articles published in the 1970s suggested "that the original findings had been false or exaggerated". In a 2009 research review in the Annals of the New York Academy of Sciences, William Bushell, quite to the contrary, referred to the original research as "classic," and said that the preponderance of evidence has shown a reduction in metabolic rate.

Contraindications

While meditation is usually considered safe, Transcendental Meditation may be contraindicated for those with psychiatric illnesses. According to a textbook on alternative and complementary medicine by Lyn Freeman, in this situation it is best if meditation is introduced in the context of a clinical setting, and those patients who are seriously disturbed should only be introduced to meditation under the supervision of a doctor or psychotherapist. Individuals with moderate symptoms were observed to benefit from the practice.

Research quality

Popular media and scholars have criticized the quality of the research, though some have identified selected studies that are high quality. According to The Jerusalem Post, The Canadian, and the Encyclopedia of Occultism & Parapsychology, some of the research has been "criticized for bias and a lack of scientific evidence", for "methodological flaws, vague definitions, and loose statistical controls", and for "failing to conduct double-blind experiments" and for "influencing test results with the prejudice of the tester". According to Newsweek, early research was "not of high caliber", failing to adequately address self-selection and the placebo effect, but later research has been "much more rigorous". Research on Transcendental Meditation has been published by the American Medical Association and the American Heart Association, as well as other medical journals such as the American Journal of Hypertension, the American Journal of Cardiology, and the International Journal of Psychophysiology. Research reviews have identified some studies as being "well-designed," "rigorous," or "high quality."

Most of the 700 studies on TM have been produced by researchers directly associated with the TM movement and many of them have not been peer reviewed, according to a 2003 review that looked at the effects of TM on cognitive function and an article in Student BMJ. Articles in the Jerusalem Post and Wall Street Journal, and a review by Canter and Ernst (2004), said that many studies have been conducted by devotees or researchers at universities tied to the Maharishi, including Maharishi University of Management in Iowa and Maharishi European Research University in Switzerland, which is disputed by Orme-Johnson, who cites the number of institutions worldwide where the research has been conducted. He also says that a meta-analyses of studies on TM and anxiety found that those studies done by researchers with no connection to TM showed a slightly larger effect than those studies by researchers who had a connection. According to TM researchers, studies on Maharishi Vedic Approach to Health have been conducted at over 200 different research institutions and universities in over 30 countries worldwide. TM promoter and physician Roger A. Chalmers compiled a list of 341 studies on TM that he says were published in "independent peer-reviewed journals or other edited scientific publications".

Canter and Ernst's 2004 review of the five published studies on blood pressure which met their basic criteria said that they had important methodological weaknesses and were potentially biased by the affiliation of authors to the TM organization. It concluded that to date (May 2004), there was "insufficient good-quality evidence to conclude whether or not TM has a cumulative positive effect on blood pressure". In response, TM researchers said that most of the studies in the review were funded by various institutes of the National Institutes of Health and that, as such, the methodologies were peer-reviewed by experts.

A 2007 U.S. government-sponsored review of research on meditation, including Transcendental Meditation, yoga, tai chi, qi gong, mindfulness, and others, said that firm conclusions on health effects cannot be drawn, as the majority of the studies are of poor methodological quality. The review included studies on adults through September 2005, with a particular focus on research pertaining to hypertension, cardiovascular disease, and substance abuse. The review used the Jadad scale to assess quality of the studies using control groups and Newcastle-Ottawa Scale for the others. The quality assessment portion of the 2007 review was published in 2008. The article stated that "Most clinical trials on meditation practices are generally characterized by poor methodological quality with significant threats to validity in every major quality domain assessed". The authors found that there was a statistically significant increase in the quality of all reviewed meditation research, in general, over time between 1956 and 2005. Of the 400 clinical studies, 10% were found to be good quality. A call was made for rigorous study of meditation. These authors also noted that this finding is not unique to the area of meditation research and that the quality of reporting is a frequent problem in other areas of complementary and alternative medicine (CAM) research and related therapy research domains.

TM researchers said that the 2007 review suffered from various limitations related to data collection, analysis, and reporting procedures. Researchers affiliated with Maharishi University of Management and the University of Kentucky said that the use of double blinding, which is required by the Jadad scale, is not appropriate to meditation research and that the review failed to assess more relevant determinants of research quality. Research reviews in science journals say that double blinding may not be possible in meditation research. Canter and Ernst say that blinding of participants isn't feasible., and a Cochrane review says that it's only possible to blind the raters or assessors in meditation trials. One of the earliest double-blinded placebo studies of Transcendental Mediation was conducted in 1975, but the 2007 government-sponsored review found this study and none of the other 800 studies reviewed were properly double blinded.

Research funding and promotion

In 1991, The Journal of the American Medical Association (JAMA) published an article on Ayer Veda of which the Transcendental Meditation technique is a part. Later, allegations were made saying that the authors Deepak Chopra, Hari M. Sharma, and Brihaspati Dev Triguna had failed to disclose that they were "involved in organizations that promote and sell the products and services about which they wrote."

In 1999, the National Center for Complementary and Alternative Medicine awarded a grant of nearly $8 million to Maharishi University of Management to establish the first research center specializing in natural preventive medicine for minorities in the U.S. According to the MUM website, the research institute, called the Institute for Natural Medicine and Prevention (INMP), was inaugurated on October 11, 1999, at the University's Department of Physiology and Health in Fairfield, Iowa. By 2004, the U.S. government had awarded more than $20 million to Maharishi University of Management to fund research.

In 2009, the National Institutes of Health awarded an additional grant of $1 million distributed over two years for research on the use of TM in the treatment of coronary heart disease in African-Americans. The award was for research in collaboration with the INMP and Columbia University Medical Center in New York City. The award was from the American Recovery and Reinvestment Act of 2009 via the National Heart, Lung and Blood Institute.

According to a 1980 article by sociologist Hank Johnston, the movement's two main universities, Maharishi International University (now Maharishi University of Management) and Maharishi European Research University, have been significant sources of the studies used in promotional materials. Leading individuals and organizations associated with TM cite the existence of many studies, "more than 600 published research studies, conducted at over 200 independent research institutions in 33 countries", to support TM-related concepts. The quantity of studies have been cited to support the political programs of the Natural Law Party, the tax status of a TM property, the use of TM to rehabilitate prisoners, the teaching of TM in schools, the issuance of bonds to finance the movement, as proof that TM is a science rather than a religion, to show the efficacy of the Maharishi Vedic Approach to Health, and as a reason to practice TM itself.

See also

• Research on meditation