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APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-08-18). The draft was written by AI, the existence of all 3 cited sources was verified at the original page, and the verdict passed blind grading and adversarial audit. Methodology v0.7.
Verdict No. 2867 · Search date 2026-08-18 · Methodology v0.7

Ten-lesson universal school-based mindfulness training,
does it really help with Improved one-year depression risk, social-emotional-behavioral functioning, and well-being in adolescents?

30-Second Summary
D
Evidence Grade D · 30 · Safety caution
Universal school mindfulness did not improve one-year depression risk, social-emotional-behavioral functioning, or well-being
No intervention-related adverse events were reported. However, several of 28 secondary outcomes, including hyperactivity-inattention and panic or obsessive-compulsive scores, moved slightly in a worse direction, so universal programs should monitor deterioration and avoid delaying clinical care for pupils who need it.
What the
research shows
The grade is D with 30 points. MYRIAD randomized 85 UK schools with 8,376 pupils at the school level. Standardized between-group differences for the three one-year co-primary outcomes were 0.005 (95% CI -0.05 to 0.06) for depression risk, 0.02 (-0.02 to 0.07) for social-emotional-behavioral functioning, and 0.02 (-0.03 to 0.07) for well-being; all were null.
What the
ads claim
Korea has policy and development activity for mindfulness and emotional-education programs offered in schools, including plans for an all-student program and a Korean school mindfulness curriculum with instructor training and pilot schools. This large null trial therefore matters directly to universal implementation. Verdict 2215 is C with 46 points for an adult worker mindfulness app: the population and delivery differ - that is an adult workplace app, whereas this is an adolescent school lesson.
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Useful facts when choosing a product

  • SBMT consisted of ten teacher-delivered psychoeducation and mindfulness-practice lessons, with pupils receiving a mean of 9.0 sessions.
  • The control was usual school social-emotional teaching, not no treatment.
  • The paper reported no intervention-related adverse events.
  • Among 28 secondary outcomes, self-reported hyperactivity-inattention, panic, obsessive-compulsive symptoms, and teacher-rated emotional symptoms included small worse-direction signals.
Gap Measurement · Verdict 2867 · D 30
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

Eighty-five schools consented and were assigned to 43 usual-teaching schools with 4,232 pupils or 42 mindfulness schools with 4,144 pupils. The allocation method was: "Following collection of baseline data, schools were randomised in a 1:1 ratio to trial arms by an independent researcher otherwise unconnected with the trial. The independent statistician generated the allocation sequence." Cluster concealment was implemented because "all schools were recruited before randomisation and allocated en bloc for each cohort," and pupils were recruited before school allocation. One school withdrew after allocation. Primary data covered 3,678/4,232 (86.9%) and 3,572/4,144 (86.2%), making primary-population missingness 13.4%, below the 15% threshold; modified intention-to-treat sensitivity analyses agreed. Limitation name: unmasked subjective endpoint Which listed item: unmasked subjective endpoint Original evidence that the requirement was met: the co-primary measures were "CES-D," "SDQ," and "WEMWBS," centered on self-report, and schools, teachers, and pupils necessarily knew whether ten mindfulness lessons were delivered. Could it have been avoided: possible - an expectancy- and contact-matched comparison curriculum plus allocation-masked independent assessment could have reduced reporting expectancy. Usual social-emotional education was existing school provision, so withholding it for a no-treatment condition was not treated as an avoidable active-control-only flaw. The Wellcome Trust funded the work and the NIHR Clinical Research Network supported it.

02

Why this is classified as D (30)

This large publicly funded cluster trial measured directly important symptoms and functioning, but all three co-primary outcomes were null. With no independent repeated trial or prespecified exclusion margin and one unmasked subjective-outcome limitation, the grade is D with 30 points.

Counterpoint. MYRIAD tested universal classroom delivery to all pupils aged roughly 11 to 14. It does not generalize to treatment for an individual diagnosed with depression, clinician-guided therapy, or an adult meditation app.

Rejudgment record. Cross-check applied — Cross-checked ISRCTN86619085 and the article for school-level concealment, three co-primary scales, confidence-interval tails, analysis population, and Wellcome-NIHR support

Scoring profile behind this grade
EndpointPPatient-reported treatment goal - the symptom is the goal
ReplicationR1Single confirmatory trial
IndependenceI2Decisive evidence is publicly or non-profit funded
Effect sizeE0Null
PrecisionC0The confidence interval leaves room for benefit

The scoring table and the verdict agree (D).

Sub-claim grades by effect

This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.

Effect (sub-claim)GradeBasis
Improved adolescent mental health at one year through universal school lessonsDAll three co-primary outcomes were null.
Ineffectiveness of individually targeted therapeutic mindfulness?MYRIAD did not test that population or delivery model.

Cross-check — Codex and Claude

This verdict was drafted by Codex through literature review and source-existence checks, cross-checked through blind grading and adversarial audit, and settled by reapplying the methodology boundary rules. Cases with split grades were resolved through rejudgment.
03

Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Study 1UK parallel cluster-randomized trial with schools as clusters and usual teaching as control7,250Funded by the Wellcome Trust with NIHR Clinical Research Network supportOne-year co-primary CES-D depression risk, SDQ social-emotional-behavioral functioning, and WEMWBS well-beingSMD 0.005 (-0.05 to 0.06), 0.02 (-0.02 to 0.07), and 0.02 (-0.03 to 0.07)Pivotal large nonprofit-funded cluster trial
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Receipt — 3 References

All 3 cited sources were verified for existence at the original page (as of 2026-08-18).

Kuyken W, Ball S, Crane C, et al. Effectiveness and cost-effectiveness of universal school-based mindfulness training compared with normal school provision in reducing risk of mental health problems and promoting well-being in adolescence: the MYRIAD cluster randomised controlled trial. Evid Based Ment Health. 2022;25(3):99-109. PMID: 35820992. ISRCTN86619085.
checked
ISRCTN86619085. MYRIAD trial registration.
checked
Reference 3
checked
Draft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-08-18 · Corrections: none

Cite this verdict

Universal School-Based Mindfulness Training Is Ineffective for Adolescent Mental Health Evidence Grade D card
[Chamgap] Universal School-Based Mindfulness Training Is Ineffective for Adolescent Mental Health — Evidence Grade D·30. 3 cited sources checked. Source: https://chamgap.com/en/verdicts/mood/universal-school-mindfulness-adolescent-mental-health/ · CC BY 4.0

CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.

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