The Tapping Evidence Base
Depression · PTSD & Trauma

Veterans PTSD gene-expression trial — depression outcome (as tabulated in Nelms & Castel 2016)

Church, D., et al. · 2018

Randomized trial👥 16 participants⚖️ vs. treatment as usual📈 Cohen's 0.9 (large)Moderate rigor📍 United States
In plain English. In this small veterans' trial, tapping sessions were linked to a solid improvement in depression alongside changes in gene activity that researchers measured in blood samples — an early attempt to find a biological explanation for tapping's effects, not yet independently replicated at scale.

What they found

Cohen's = 0.9
a large effect · on depressive symptoms (SA-45 subscale; figure from the Nelms & Castel secondar
smallmoderatelarge
00.50.82.5

Depression symptoms decreased by 38% (d=0.9). This trial is also discussed in Church et al. 2022 for finding significant differential expression of six genes (p<0.05) alongside symptom improvement, and its PTSD outcome appears in the Sebastian & Nelms 2017 table (d=2.18).

How the study worked

Who took partveterans with PTSD (n=16)
What they didIn a randomized controlled trial, participants were randomly assigned to receive tapping or a comparison condition, then measured and compared.
Compared withtreatment as usual
Measured withSA-45

⭐ Why this study matters

This is a big deal because gene expression is about as close to hard biology as psychological research gets — genes switching on or off in response to an intervention is not something a person can talk themselves into. Finding measurable differential gene expression alongside symptom improvement is a striking, unusual result, and if it holds up in larger samples, it would give tapping a genuinely molecular account of what might be happening in the body, not just a psychological one.

💡 Where this could help

If a biological signature like this is confirmed in larger studies, picture veterans with PTSD-related depression getting a treatment whose effects can eventually be measured in blood tests, not just self-report questionnaires, giving skeptical clinicians and patients more concrete evidence that something real is happening in the body even when the technique itself is something the veteran administers alone, without a clinician watching each session. That kind of biological grounding could help the approach gain broader acceptance in mainstream medicine.

🔬 What to study next

With six genes already flagged as differentially expressed alongside the depression improvement, the compelling next step is figuring out exactly which genes and pathways are involved — immune and inflammatory genes, HPA-axis-related genes, and genes tied to neuroplasticity are all plausible candidates in PTSD-linked depression. A larger sample with a broader gene panel, paired with cortisol and inflammatory markers, could start to map an actual biological pathway running from tapping session to gene activity to symptom change.

The full record

DesignRandomized trial
Participants16 people
Populationveterans with PTSD
Comparison grouptreatment as usual
Effect sizeCohen's d = 0.9 — on depressive symptoms (SA-45 subscale; figure from the Nelms & Castel secondary table, not stated in the primary paper)
Outcome measuresSA-45
JournalOriginal publication venue not confirmed (indexed via Nelms & Castel 2016 Table 4; note the meta-analysis was published in 2016, so this citation's 2018 date is likely a later-added/renumbered reference in the secondary source)
Year2018
CountryUnited States
LanguageEnglish
MethodEFT / tapping
Publication typeStudy / trial
VerificationTranscribed from a peer-reviewed source; pending independent confirmation
Verification note. N=16, RCT design (EFT vs TAU), 10 sessions/10 weeks, and 6 differentially-expressed genes (P<.05) all confirmed via the accessible Europe PMC abstract, along with the -53% PTSD symptom reduction. The specific depression Cohen's d=0.9 (SA-45 subscale) is NOT stated in the accessible abstract itself (full text is paywalled) — left unchanged rather than invented; this one figure traces to the Nelms & Castel 2016 secondary table per source_of_record and remains an open, unconfirmed detail even though the record's core metadata is now verified. The 2016/2018 dual citation date is a genuine cross-index quirk, not an error.

Read the original study →

Cite this study

APA

Church, D., & et al. (2018). Veterans PTSD gene-expression trial — depression outcome (as tabulated in Nelms & Castel 2016). https://doi.org/10.1177/0890117116661154

This record is part of the Tapping Evidence Base — an openly-sourced, fully-referenced directory of the research on EFT/tapping. Explore more studies on Depression · PTSD & Trauma

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THE TAPPING EVIDENCE BASE Depression Cohen's 0.9 large effect WHAT THEY FOUND Depression symptoms decreased by 38%(d=0.9). This trial is also discussed inChurch et al. 2022 for finding… Randomized trial · 16 participants Church · 2018 · evidence.thetappingsolution.com