Hoeveel verlaagt Transcendente Meditatie de bloeddruk volgens onderzoek?

Een meta-analyse van 23 gerandomiseerde trials (Rainforth e.a., Current Hypertension Reports, 2007) vond een gemiddelde daling van 5,0 mmHg systolisch en 2,8 mmHg diastolisch. Op basis van dit type onderzoek concludeerde de American Heart Association in 2013 dat TM als enige onderzochte meditatietechniek de bloeddruk aantoonbaar verlaagt en overwogen kan worden in de klinische praktijk.

Is er onderzoek naar TM en hartinfarct- of beroertepreventie?

Ja. Een gerandomiseerde trial onder 201 Afro-Amerikanen met coronaire hartziekte (Schneider e.a., Circulation: Cardiovascular Quality and Outcomes, 2012) vond een 48% relatieve risicoreductie op het samengestelde eindpunt van hartinfarct, beroerte en cardiovasculaire sterfte, gemeten over gemiddeld 5,4 jaar.

Is TM-onderzoek onafhankelijk gepubliceerd en beoordeeld?

De kernstudies over TM zijn gepubliceerd in tijdschriften zonder institutionele band met de TM-organisatie, zoals Circulation, Hypertension, JAMA Network Open, Frontiers in Medicine en Intelligence, en zijn daar onderworpen aan onafhankelijke peer review. Tegelijk is een deel van de onderzoekers verbonden aan de Maharishi University of Management, wat critici terecht als aandachtspunt benoemen (Canter & Ernst, Journal of Hypertension, 2004) — dit whitepaper bespreekt die kritiek expliciet in plaats van deze te verzwijgen.

Wat toont onderzoek over TM en angst?

De grootste meta-analyse (Orme-Johnson & Barnes, Journal of Alternative and Complementary Medicine, 2014) bundelde 16 gerandomiseerde trials met 1.295 deelnemers en vond een effectgrootte van d=-0,50 tot -0,62 op angstklachten, vergelijkbaar met een middelgroot tot groot effect.

Helpt TM bij posttraumatische stressstoornis (PTSS)?

Een meta-analyse van 15 gecontroleerde trials met 1.248 deelnemers (Orme-Johnson, Barnes, Rees & Tobin, Medicina, 2025) vond een groot gepoold effect (g=-1,01) op PTSS-symptomen, en TM was niet-inferieur aan en sneller werkzaam dan langdurige exposuretherapie. Een bredere meta-analyse van 61 studies met 3.440 deelnemers (2024) vergeleek vier soorten meditatie: TM had het grootste effect (g=-1,13), significant groter dan MBSR, andere mindfulness en overige meditatie.

Is er onderzoek naar TM en schoolprestaties?

Op een middelbare school die het Quiet Time-programma (TM tijdens schooltijd) invoerde, was het diploma-percentage van mediterende leerlingen 87,1% tegenover 66,7% bij niet-mediterende leerlingen, met het grootste verschil bij leerlingen met een laag gemiddelde (Colbert & Nidich, Education, 2013).

Scientific Research on Transcendental Meditation

Domain I

Stress & Mental Health

Anxiety, burnout, and post-traumatic stress are the most frequently studied outcome measures within the TM research field.

Anxiety: The Largest Meta-Analysis to Date

The most comprehensive analysis of TM and anxiety pooled 16 randomized trials with a total of 1,295 participants. Compared with active alternative treatments, the effect was d = −0.50; compared with usual care or a waiting list, the effect was d = −0.62—in both cases, a moderate to large effect. Participants with anxiety scores in the 90th percentile at baseline dropped, on average, to the 57th percentile after a TM intervention.

Burnout among healthcare staff

A randomized trial involving 80 healthcare workers compared TM to a control group over a three-month period. On the primary outcome measure (general psychological symptoms), the difference was not statistically significant—we note this here deliberately. On three secondary outcome measures, however, the difference was statistically significant:

Outcome Measure	TM group	Control group	p-value
Emotional exhaustion	−8.0 pts	−2.6 pts	0.006
Anxiety (GAD-7)	−3.1 pts	−0.9 pts	0.01
Insomnia (ISI)	−4.1 pts	−1.9 pts	0.05

Post-traumatic stress

The most recent and largest meta-analysis focuses on PTSD: 15 controlled trials, 1,248 participants, ranging from military personnel with combat trauma to refugees from Ukraine and the Congo. The pooled effect size was large (g = −1.01). Compared to prolonged exposure therapy—the standard first-line treatment—TM was non-inferior and worked faster.

Those trials follow a broader meta-analysis by the same group (2024) that compared all forms of meditation for PTSD side by side: 61 studies, 3,440 participants, in four categories. The pre-post effect size was g = −1.13 for TM, against −0.52 for MBSR, −0.66 for other mindfulness-based interventions and −0.63 for other meditations. The difference between TM and each of the other three was statistically significant; study characteristics (outcome measures, control conditions, populations) did not differ appreciably between categories [19].

Cortisol and the HPA axis

A smaller, exploratory trial in young adults measured levels directly in the body: participants who learned TM had lower morning cortisol levels after four weeks than the waitlist group. This is a pilot study with a limited sample size—a signal that calls for replication, not an established fact.

Domain II

Heart and Blood Vessels

The field in which TM is the only meditation technique included in an official guideline from the American Heart Association.

Blood Pressure: The Most Widely Reproduced Effect

A meta-analysis of 23 high-quality trials found an average reduction of 5.0 mmHg in systolic blood pressure and 2.8 mmHg in diastolic blood pressure—greater than that observed with biofeedback, progressive muscle relaxation, or general stress management programs. Based on this type of research, the American Heart Association concluded in 2013 that TM modestly lowers blood pressure and can be considered as an adjunct in clinical practice—the only meditation technique among the methods studied that met that criterion.

Hard outcomes: heart attack, stroke, mortality

Blood pressure is an intermediate measure. More convincing is a randomized trial involving 201 African Americans with existing coronary heart disease, followed for an average of 5.4 years: the TM group had a 48% lower risk of the composite endpoint of heart attack, stroke, and cardiovascular mortality (HR 0.52; p = 0.025). A secondary, broader endpoint showed a non-significant 24% reduction (p = 0.17)—not every reported result from this trial met the statistical threshold, and we are deliberately noting this.

A later, independently published trial in a comparable high-risk population (197 participants) followed participants for up to 14 years and found a 65% relative risk reduction in serious cardiovascular events at the five-year follow-up, rising to 93% in the first year—an effect that waned over the longer term. Notably, the physical thickness of the arterial wall differed only slightly between the groups, suggesting that the benefit is not primarily mediated by plaque regression but rather via the autonomic nervous system.

Domain III

Cognition & Learning

From academic performance to cognitive test scores: the domain with the longest tradition of research.

Quiet Time at School

In schools that implemented the “Quiet Time” program—a set time at the beginning and end of the school day when students are allowed to practice TM or silent reading—the graduation rate among meditating seniors was significantly higher than that of non-meditating students, with the greatest difference observed among students with lower grade point averages. At another school, after eight months of Quiet Time, ninth-graders scored significantly lower on anxiety and higher on resilience than a comparison group.

Cognitive test performance

Three randomized experiments involving 362 high school students in Taiwan tested TM across seven cognitive measures. On all seven measures, TM performed significantly better than an untreated control group; on five of the seven, it also performed significantly better than a standalone form of contemplative meditation. Simply napping had no effect on any of the measures. An earlier two-year study involving 100 college students found a significant improvement on an intelligence test (CFIT) in the TM group compared to a control group that showed no improvement (t = 2.79; p < 0.005).

Nieuw · augustus 2026

Wat er in het brein gebeurt tijdens TM

De nieuwste publicatie op deze pagina meet geen klachten die afnemen, maar de toestand tijdens het mediteren zelf.

Onderzoekers van de afdeling Psychologie van de University of Cambridge maten met high-density EEG wat er gebeurt bij 33 ervaren TM-beoefenaars, naast 33 op leeftijd en geslacht gematchte niet-mediterenden. Beide groepen zaten eerst tien minuten met gesloten ogen, deden daarna dertig minuten TM of een mentale teltaak, en sloten af met tien minuten rust. De beoefenaars mediteerden gemiddeld 12,9 jaar. Aan het onderzoek werkten collega's van zes andere universiteiten mee.

Drie bevindingen

De toestand is meetbaar anders dan gewoon stil zitten. Tegenover hun eigen rust met gesloten ogen was gecoördineerde, laagfrequente activiteit tussen hersengebieden het sterkste onderscheid. De onderzoekers beschrijven de toestand als gevarieerder dan gewone denkactiviteit en tegelijk meer geordend dan rust. Een stiller hoofd betekent dus geen stiller brein.

Het patroon verdween na de sessie. De EEG-kenmerken van de meditatie liepen nauwelijks door in de rustperiode erna, terwijl de veranderingen bij de teltaak dat wél deden. Dat wijst op een tijdelijke toestand tijdens de beoefening zelf, niet alleen op een blijvend verschil tussen mensen die mediteren en mensen die dat niet doen.

Jaren ervaring maakten niet uit. Hoe sterk deelnemers de toestand rapporteerden, hing niet samen met hoe lang ze TM al beoefenen. Dat past bij hoe de techniek wordt onderwezen: moeiteloos, zonder vaardigheid die eerst opgebouwd moet worden.

Wat deze studie niet laat zien

Het gaat om een verband tussen gerapporteerde ervaring en hersenpatronen. Geen oorzaak, en geen gezondheidseffect. De groep is klein, de ervaringskant berust op zelfrapportage, en tellen is als controletaak geen perfecte spiegel van mediteren. Het onderzoek werd gefinancierd door de David Lynch Foundation UK uit particuliere giften, die ook de TM-deelnemers wierf; de controlegroep kwam via Cambridge. Uitvoering en analyse lagen bij de universiteiten, en het artikel verscheen na peer review in Journal of Cognitive Neuroscience.

What controlled research in the workplace shows

These are the randomised trials of TM among working people, each with a control group. For every study you can see who took part, what TM was compared with and what changed.

Study	Participants	Compared with	Result
Khanal et al., J Affect Disord, 2026 · PubMed 42778032	129 staff at an Australian university	Usual wellbeing resources, 6 months	Lower perceived stress (effect size g = −0.52), less anxiety, depression and burnout, better sleep and quality of life. Productivity impairment was also measured; the abstract reports no significant effect there.
Joshi et al., JAMA Network Open, 2022 · PubMed 36121655	80 health care workers, Duke University	Usual wellbeing resources, 3 months	Emotional exhaustion fell 5.4 points more, with less insomnia and anxiety. The primary outcome, acute psychological distress, did not differ significantly.
Bonamer et al., J Nurs Adm, 2024 · PubMed 38078959	104 nurses in 3 hospitals	Wait-list group, 3 months	Less burnout, anxiety and post-traumatic stress, more flourishing.
Elder et al., Perm J, 2014 · PubMed 24626068	40 teachers and support staff at a therapeutic school	Wait-list group, 4 months	Less perceived stress, depression and burnout.

The wider picture: a meta-analysis of 132 randomised trials with 23,080 employees, mostly mindfulness and TM, found lower stress (g = −0.51) and higher wellbeing (g = 0.41). It found no significant effect on blood pressure or cortisol. The authors rate the certainty of the evidence as moderate for wellbeing and sleep and low to very low for the other outcomes (Khanal et al., Health Psychology Review, 2026 · PubMed 41987765).

What these trials do not show: hard productivity figures such as output or revenue. A provider who promises those goes further than the research.

Critical Review

Methodological notes

A source of authority that presents only favorable results is not a source of authority.

The question of independence

A significant proportion of the authors cited above are affiliated with Maharishi University of Management, an institution with historical ties to the TM organization. Critics have rightly identified this as a legitimate cause for concern: a 2004 systematic review (Canter & Ernst, Journal of Hypertension) concluded that, at the time, there was insufficient high-quality research to determine whether TM lowers blood pressure, and explicitly recommended that future research be conducted by researchers with no ties to the TM movement. A comprehensive 2007 AHRQ report characterized the majority of the meditation research field in general—not specifically TM—as methodologically weak.

What is verifiable, however, is that the key studies on this page were published after that criticism, in journals with no institutional ties to TM— *Circulation*, *Hypertension*, *JAMA Network Open*, *Frontiers in Medicine*, *Medicina*, and *Intelligence* —and were subjected to independent peer review there. Furthermore, the American Heart Association’s 2013 position statement comes from a completely independent medical body with no ties to TM.

What’s still missing

Not every finding here has been replicated on a large scale by completely external research groups. The cortisol study is a small pilot study. The two cardiovascular trials come from the same research line and population, which limits their generalizability. Future, independently funded replication remains desirable.

For transparency: two sources in the reference list, [16] and [17], have the chair of TM Nederland, dr. Paul Gelderloos, as co-author. His publications are listed on ORCID.

Volledige bronnenlijst

[1] 48% relative risk reduction for heart attack, stroke, or death in patients with coronary heart disease (n=201, mean 5.4 years).

Schneider RH et al. — Circ Cardiovasc Qual Outcomes, 2012

[2] 65% relative risk reduction for serious cardiovascular events at 5 years (n=197), 93% at 1 year.

Norris KC et al. — Frontiers in Medicine, 2025

[3] Blood pressure reduction of 5.0/2.8 mmHg, meta-analysis of 23 trials from 107 screened publications.

Rainforth MV et al. — Curr Hypertens Rep, 2007

[4] TM is the only meditation technique studied that has been shown to lower blood pressure in clinical practice.

Brook RD et al. (AHA) — Hypertension, 2013

[5] Effect size d = −0.50 to −0.62 for anxiety, 16 trials, 1,295 participants.

Orme-Johnson DW, Barnes VA — J Altern Complement Med, 2014

[6] Significant reduction in emotional exhaustion, anxiety, and insomnia among healthcare workers (n=80).

Joshi SP et al. — JAMA Network Open, 2022

[7] Large pooled effect (g = −1.01) on PTSD, 15 trials, 1,248 participants; non-inferior to exposure therapy.

Orme-Johnson DW et al. — Medicina, 2025

[8] Lower morning cortisol levels after 4 weeks of TM in young adults (pilot study).

Klimes-Dougan B et al. — Stress, 2020

[9] Graduation rate: 87.1% vs. 66.7% among students in the Quiet Time program (n=235).

Colbert RD, Nidich S — Education, 2013

[10] Significantly lower anxiety and higher resilience among Quiet Time students (n=141 vs. 53).

Wendt S et al. — Contemp Sch Psychol, 2015

[11] TM was significantly better than the control group on 7 out of 7 cognitive measures among 362 students in Taiwan.

So KT, Orme-Johnson DW — Intelligence, 2001

[12] Significant improvement on an intelligence test (CFIT) after 2 years of TM, with a control group (n=100).

Cranson RW et al. — Pers Individ Dif, 1991

[13] Comprehensive evidence report: the majority of 813 meditation studies are methodologically weak (not TM-specific).

Ospina MB et al. — AHRQ Evidence Report 155, 2007

[14] Insufficient high-quality evidence at the time regarding TM and blood pressure; call for independent follow-up research.

Canter PH, Ernst E — J Hypertension, 2004

[15] Meetbaar andere, tijdelijke hersendynamiek tijdens TM dan tijdens rust of een teltaak (hd-EEG, n=33+33).

Chandia-Jorquera A e.a. — J Cogn Neurosci, 2026 · PubMed 42213535

[16] Review of the evidence for the TM programme in preventing and treating substance misuse.

Gelderloos P, Walton KG, Orme-Johnson DW, Alexander CN — Int J Addict, 1991 · PubMed 1889927 · doi:10.3109/10826089109058887

[17] Preliminary support for a psychoneuroendocrine mechanism linking stress reduction to the prevention of hypertension.

Walton KG, Pugh ND, Gelderloos P, Macrae P — J Altern Complement Med, 1995 · PubMed 9395623 · doi:10.1089/acm.1995.1.263

[18] American Heart Association scientific statement: meditation, including TM, may be considered as an adjunct to guideline-directed cardiovascular risk reduction (Class IIb).

Levine GN et al. (AHA) — J Am Heart Assoc, 2017 · PubMed 28963100

[19] Meditation for PTSD, 61 studies, 3,440 participants: TM g = −1.13 vs. MBSR −0.52, other mindfulness −0.66, other meditations −0.63; TM significantly larger than each.

Orme-Johnson DW, Barnes VA, Rees B, Tobin J, Walton KG — Medicina, 2024 · PubMed 39768929 · doi:10.3390/medicina60122050

A meta-analysis of 23 randomized trials found an average reduction of 5.0 mmHg in systolic blood pressure and 2.8 mmHg in diastolic blood pressure. Based on this type of research, the American Heart Association concluded in 2013 that TM is the only meditation technique studied that demonstrably lowers blood pressure.

Read the full chapter on the heart and blood vessels →

Yes. A randomized trial involving 201 African Americans with coronary heart disease found a 48% relative risk reduction for the composite endpoint of heart attack, stroke, and cardiovascular mortality, measured over an average of 5.4 years.

The core studies have been published in journals with no institutional ties to the TM organization and have undergone independent peer review there. At the same time, some of the researchers are affiliated with Maharishi University of Management—a valid point of concern that critics rightly raise.

Read the full methodological notes →

The largest meta-analysis pooled 16 randomized trials involving 1,295 participants and found an effect size of d = −0.50 to −0.62 on anxiety symptoms, comparable to a medium- to large-sized effect.

A meta-analysis of 15 controlled trials involving 1,248 participants found a large pooled effect (g = −1.01) on PTSD symptoms. TM was non-inferior to and acted more quickly than prolonged exposure therapy, the standard first-line treatment.

A broader meta-analysis of 61 studies with 3,440 participants (2024) compared four kinds of meditation for PTSD: TM had the largest effect (g = −1.13), significantly larger than MBSR (−0.52), other mindfulness (−0.66) and other meditations (−0.63).

At a high school that implemented the Quiet Time program, the graduation rate for students who meditated was 87.1%, compared to 66.7% for students who did not meditate, with the greatest difference observed among students with low grade point averages.

Read the full chapter on cognition & learning →

Transcendental Meditation: A Scientific Overview