Verdict No. 3005 · Search date 2026-09-07 · Methodology v0.9
Laughter-yoga sessions combining clapping, breathing, and group activities,
does it really help with Reduced perceived stress in nonclinical students and nurses?
30-Second Summary
C
Evidence Grade C · 50 · Safety unknown
A perceived-stress signal in nonclinical adults should not be expanded to cortisol reduction or treatment of mental disorders
Arm-specific adverse-event and long-term safety data were sparse. Stop for hyperventilation, dizziness, abdominal pressure, or pain; people soon after surgery or with hernia or serious cardiopulmonary disease should seek clinical guidance.
What the
research showsGrade C with 50 points. In a 70-person trial of psychiatric nurses, the PSS group-by-time result was F(1,68)=251.56, P<.001, partial eta-squared .787. A no-intervention control, lack of blinding, combined instructor-assessor role, and registration-timing concerns limit confirmation, while cortisol findings were inconsistent across studies and sessions.
research showsGrade C with 50 points. In a 70-person trial of psychiatric nurses, the PSS group-by-time result was F(1,68)=251.56, P<.001, partial eta-squared .787. A no-intervention control, lack of blinding, combined instructor-assessor role, and registration-timing concerns limit confirmation, while cortisol findings were inconsistent across studies and sessions.
What the
ads claimThe claim that laughter lowers cortisol and therefore treats depression extends nonclinical stress scales and inconsistent biomarkers to treatment of disease.
ads claimThe claim that laughter lowers cortisol and therefore treats depression extends nonclinical stress scales and inconsistent biomarkers to treatment of disease.
Useful facts when choosing a product
- Laughter yoga combines laughter with clapping, breathing, playful movement, and group interaction.
- Humorous video is a separate intervention and cannot be credited to laughter yoga.
- Psychiatric nurses are not psychiatric patients.
Gap Measurement · Verdict 3005 · C 50
What the research actually shows
A 120-person healthy-student trial acutely compared laughter yoga, humorous video, and reading. Trials in 75 and 83 nursing students and 70 psychiatric nurses compared five-week or eight-session group programs with controls. None tested treatment of psychiatric patients.
Why this is classified as C (50)
A patient-reported endpoint with R1 and I2 is capped by unclear prespecification EX and small, short, unblinded B2 studies, giving C with 50 points.
Counterpoint. Cortisol is weaker, around C46, because session-level results were mixed and precise between-group intervals were unavailable.
Rejudgment record. Cross-check applied — Separated stress and mental-symptom scales from cortisol, did not transfer humorous-video or group-participation effects to laughter yoga, and incorporated retrospective registration and conflicting statistical descriptions
Scoring profile behind this grade
| Endpoint | P | Patient-reported treatment goal - the symptom is the goal |
| Replication | R1 | Single confirmatory trial |
| Independence | I2 | Decisive evidence is publicly or non-profit funded |
| Effect size | EX | The clinical size of the effect could not be judged |
The scoring table and the verdict agree (C).
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) | Grade | Basis |
|---|---|---|
| Reduced perceived stress in nonclinical adults | C | Positive trials exist, but no-intervention controls, prespecification, and blinding remain concerns. |
| Reduced salivary cortisol | C | Laughter specificity and session-to-session consistency are insufficient, leaving a weaker C46-level signal. |
| Treatment of depressive or anxiety disorders | ? | The main populations were healthy students and nurses, not patients treated for diagnosed disorders. |
Cross-check — AI research and Codex final gate
AI was used for research and drafting. Blind grading, adversarial audit, and the methodology boundary rules were then reapplied before Codex performed the final evidence, grade, copy, and build checks. If a grade cannot be narrowed, both evidence positions and their reasons are published.
Evidence Table
| Study | Design | Sample | Funding | Endpoint | Result | Weight |
|---|---|---|---|---|---|---|
| Bilgihan S, Dost A. 2026 | Randomized controlled trial | 35 | Reported no external funding or conflicts; instructor also assessed outcomes | PSS, GHQ, and burnout after eight sessions | PSS group-by-time F(1,68)=251.56, P<.001, partial eta-squared .787; trial and registration dates raised timing concerns | Key symptom trial with prespecification concern |
| Study 2 | Randomized controlled trial | 42 | Not verified | Well-being, perceived stress, and academic self-efficacy | A null between-group abstract statement coexisted with a multivariate interaction F=10.69, P<.001; registration was retrospective | Interpretation and registration qualifier |
| Ozturk FO, Tezel A. 2021 | Eight-session randomized controlled trial | 75 | Not verified | Mental symptoms and salivary cortisol | Mental symptoms favored intervention; cortisol was between-group positive in only three of eight sessions | Symptom support and mixed biomarker evidence |
| Study 4 | Three-arm laughter-yoga, humorous-video, and reading randomized trial | 120 | Not verified | Acute salivary cortisol and DHEA | Cortisol changed over time, humorous video also changed it, and DHEA was null | Laughter-specificity qualifier |
Receipt — 4 References
Of 4 cited sources, 1 had limited original-page access (blocked or summary-only) and were verified via index/summary, marked partial; the rest were verified at the original page. As of 2026-09-07.
Bilgihan S, Dost A. The effect of laughter yoga on the general health status, perceived stress and burnout levels of psychiatric nurses: a randomized controlled study. Discover Psychology. 2026;6:200. DOI: 10.1007/s44202-026-00725-4.
checkedYaş MA, et al. The effect of laughter yoga on well-being, perceived stress, and academic self-efficacy in nursing students: A randomized controlled trial. Appl Psychol Health Well Being. 2025;17:e12610. PMID: 39415513. PMCID: PMC11635907. DOI: 10.1111/aphw.12610.
checkedOzturk FO, Tezel A. Effect of laughter yoga on mental symptoms and salivary cortisol levels in first-year nursing students: A randomized controlled trial. Int J Nurs Pract. 2021;27:e12924. PMID: 33580606. DOI: 10.1111/ijn.12924.
checkedFujisawa A, et al. Effect of laughter yoga on salivary cortisol and dehydroepiandrosterone among healthy university students: A randomized controlled trial. Complement Ther Clin Pract. 2018;32:6-11. PMID: 30057059. DOI: 10.1016/j.ctcp.2018.04.005.
partialResearch and draft: AI used · Cross-check: blind grading and adversarial audit
Final verification and publication gate: Codex · Verification cutoff: 2026-09-07 · Corrections: none
Final verification and publication gate: Codex · Verification cutoff: 2026-09-07 · Corrections: none
Cite this verdict
[Chamgap] Laughter Yoga for Perceived Stress—Improvement Signal With Unclear Prespecification and Controls — Evidence Grade C·50. 4 cited sources checked. Source: https://chamgap.com/en/verdicts/cognition/laughter-yoga-perceived-stress-nonclinical-adults/ · CC BY 4.0CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.
What this document does and does not do
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