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Open questions — post-traumatic stress disorder

Last curated: 2026-09-02 (build), revised 2026-09-02 by the independent audit. All cited PMIDs and NCT IDs were retrieved live from PubMed E-utilities and the ClinicalTrials.gov v2 API in the sessions that wrote them.

17 questions (10 Tier 1 + 2 added by audit, 5 Tier 2) and 20 unconnected-dot junctions. Tier 1 questions could change practice and are designable now. Tier 2 questions require measurement, methods or a preceding answer. Stable IDs are preserved.

Tier 1 — practice-changing and designable now

OQ-1. Which therapy maximizes retention-adjusted benefit?

Adult networks rank symptom efficacy, while PTSD CBT dropout can exceed controls and routine-care rates of 38–51% motivated a 916-person direct analysis (Mavranezouli 2020, PMID 32063234; Carpenter 2018, PMID 29451967; Harper 2026, PMID 41926191). An IPD network meta-analysis can jointly model assignment, dose, dropout, post-dropout outcome and function.

OQ-2. Do effects transport across DSM-5 PTSD, ICD-11 PTSD and ICD-11 CPTSD?

The systems select non-identical populations, and ITQ-defined CPTSD is rarely stratified in treatment trials (Cloitre 2018, PMID 30178492; Brewin 2017, PMID 29029837). Existing item-level trial data could reconstruct strata.

OQ-3. Does CPTSD require phase-based treatment before trauma-focused work?

Complex-event component evidence supports benefit but does not settle fixed sequencing (Coventry 2020, PMID 32813696). A pragmatic non-inferiority/superiority trial should compare immediate trauma focus with criterion-triggered stabilisation.

OQ-4. Which prospectively defined phenotype predicts prazosin benefit?

Three positive trials conflict with the 304-person PACT null result (Raskind 2003, PMID 12562588; Raskind 2007, PMID 17069768; Raskind 2013, PMID 23846759; Raskind 2018, PMID 29414272), and two meta-analyses still rate prazosin effective for trauma-related nightmares (Yücel 2020, PMID 31855732; Zhang 2022, PMID 35661755). The leading candidate marker is pretreatment standing systolic blood pressure, where each 10 mm Hg predicted an additional 14-point CAPS reduction under prazosin but not placebo in a secondary analysis (Raskind 2016, PMID 27320368), contested in a comorbid alcohol-use-disorder sample (Manhapra 2019, PMID 30143236). Status as of the audit's live registry check on 2026-09-02: a phase 3 prazosin-versus-placebo trial designed around noradrenergic biomarkers (NCT03539614, n=87) records an actual primary completion date of 1 January 2026 and is active-not-recruiting, with no results publication indexed in PubMed. The question is therefore no longer "is anyone testing this" but "what did that trial find" — the first item to check at the next sweep.

OQ-5. Can independent MDMA replication address expectancy and therapist effects?

Phase 3 effects were d=.91 and d=.70, but the FDA declined approval in August 2024 and required another phase 3 trial (Mitchell 2021, PMID 33972795; Mitchell 2023, PMID 37709999; Wolfgang 2025, PMID 39741438; Morland 2026, PMID 41820235). A 2026 meta-analysis of eight randomized trials estimates SMD −1.19 (95% CI −1.95 to −0.42) with most studies at high risk of bias in outcome measurement (Fares-Otero 2026, PMID 41825162), and the 2026 state-of-the-science review names blinding, absent active comparators, absent head-to-head therapy-model comparisons, inadequate safety monitoring and narrow generalizability as the specific design debts. Independent funding, expectancy measurement and safety adjudication are designable now.

OQ-6. Which early intervention prevents PTSD without over-treating recovery?

Single-session debriefing is ineffective and potentially harmful, while targeted early CBT has supportive evidence (Rose 2002, PMID 12076399; Bryant 2007, PMID 21352105). A risk-stratified stepped-care trial can estimate absolute benefit and overtreatment.

OQ-7. Do military/civilian differences represent true effect modification?

Exposure meta-regression found larger effects in civilian/refugee than military studies, but study-level confounding is substantial (McLean 2022, PMID 34954460). Harmonized IPD can test within-trial interactions.

OQ-8. Does preference matching improve completion and function?

Preference matters to uptake, but assignment-by-preference can confound treatment effects (PMID 32074319; Harper 2026, PMID 41926191). A doubly randomized preference design is feasible.

OQ-9. Which pediatric TF-CBT components are necessary?

TF-CBT has the largest evidence base—52 of 70 pediatric RCTs—and g=1.06 versus passive control (Hoppen 2025, PMID 39630422). Component or sequential multiple-assignment designs could reduce burden while preserving benefit.

OQ-10. What adverse-event standard should PTSD psychotherapy trials use?

Adverse-event data were absent from most trials in a major review (Cusack 2016, PMID 26574151). A consensus taxonomy and mandatory arm-level reporting are achievable now.

OQ-16. Does psilocybin do anything for PTSD under a control condition?

The 2022 statement that no psilocybin PTSD trial existed (Khan 2022, PMID 35711024) is no longer current: two uncontrolled trials have since been published — an open-label phase 2 study in 22 participants reporting CAPS-5 change of −29.9 at week 4 (McGowan 2026, PMID 40883964) and an open-label veteran pilot in 12 participants reporting −27.5 points (95% CI 19.9–35.1) at one month (Armstrong 2026, PMID 42533157, NCT05554094). The dated gap as of 2026-09-02 is precise: 34 participants total, no control condition, and no randomized psilocybin PTSD trial published. Given that open-label PTSD trials routinely produce large within-group change, a randomized comparison is the only design that can distinguish drug effect from expectancy and regression.

OQ-17. Can a rapid-acting drug effect be separated from the therapy package it is delivered inside?

The MDMA phase 3 programme deliberately bundled drug with a manualized therapy (Mitchell 2021, PMID 33972795; Mitchell 2023, PMID 37709999), which is exactly why attribution has been contested. A phase 2 trial of the neuroplastogen TSND-201 with no psychotherapy component found a CAPS-5 advantage over placebo (LS mean difference 9.64; 90% CI −16.48 to −2.80) in 65 participants (Jones 2026, PMID 41706459, NCT05741710), and ketamine trials without a therapy package disagree with each other (Feder 2021, PMID 33397139; Abdallah 2022, PMID 35046508). A factorial drug × therapy design in one population would answer directly what the current literature only permits inferring across incomparable trials.

Tier 2 — depends on methods or prior answers

OQ-11. Is moral injury separable enough to warrant a distinct treatment pathway?

The 116-study review found no consensus definition or gold-standard measure (Griffin 2019, PMID 30688367). Measurement must separate exposure, appraisal and impairment before comparative treatment testing.

OQ-12. Can biological measures predict individual treatment response?

HPA, autonomic and imaging differences are heterogeneous group associations, not clinical predictors (Pitman 2012, PMID 23047775; Campbell 2019, PMID 30779926). Reliable assays and external validation are prerequisites.

OQ-13. Are categorical CPTSD and dimensional DSO equally prognostic?

Latent-profile studies recover classes across populations but model fit does not establish clinical thresholds (Karatzias 2017, PMID 27723542; Vang 2019, PMID 31984942).

OQ-14. Which outcomes define recovery beyond symptom loss?

Function, sleep, relationships, work, parenting and meaning are inconsistently co-primary. Trials and patient-priority studies need a core outcome set (PMID 39514500; PMID 37722204).

OQ-15. Can PTSD–pain treatment target shared avoidance without conflating outcomes?

Only 13 studies met criteria in a childhood-trauma/PTSD/CPTSD/chronic-pain review, and four explicitly tested the linkage (Karimov-Zwienenberg 2024, PMID 39213321).

Dots not yet connected

# Dot A Dot B Missing junction Powers
D1 Adult therapy NMA ranks symptoms (PMID 32063234) Direct dropout evidence exists (PMID 41926191) Retention-adjusted comparative benefit OQ-1
D2 ITQ identifies CPTSD (PMID 30178492) Most trials used DSM definitions Reconstructed diagnostic-stratum effects OQ-2, OQ-3
D3 Complex-trauma interventions can help (PMID 32813696) Phase-based care is widely proposed Randomized sequencing by measured need OQ-3
D4 Prazosin meta-analyses positive (PMIDs: 31855732, 35661755) PACT null (PMID 29414272) Published result of the completed biomarker trial NCT03539614 OQ-4
D5 MDMA phase 3 effects positive (PMIDs: 33972795, 37709999) FDA required another trial (PMID 39741438) Independent design resolving expectancy/safety OQ-5
D6 Debriefing can harm (PMID 12076399) Targeted early CBT can help (PMID 21352105) Calibrated triage threshold OQ-6
D7 Military studies dominate Civilian/refugee effects appear larger (PMID 34954460) Patient-level transport model OQ-7
D8 Preferences shape uptake (PMID 32074319) Treatments have similar active-comparator effects Randomized preference-sensitive pathway OQ-8
D9 Pediatric TF-CBT evidence is strongest (PMID 39630422) Caregiver availability/safety varies Component-by-caregiver configuration OQ-9
D10 Psychotherapy benefit is established (PMID 26574151) Adverse-event reporting is sparse Core harm taxonomy OQ-10
D11 Moral injury correlates with PTSD (PMID 33475402) No gold-standard moral-injury outcome (PMID 30688367) Discriminant measurement before treatment OQ-11
D12 Autonomic group difference exists (PMID 30779926) Therapy selection remains preference/availability-led Prospective validated treatment predictor OQ-12
D13 CPTSD profiles replicate (PMID 27723542) Prognosis is continuous Category-versus-dimension prediction OQ-13
D14 Symptom endpoints dominate Patient sources prioritize function and relationships Co-designed core outcome set OQ-14
D15 PTSD and chronic pain co-occur (PMID 39213321) Avoidance is targeted in both fields Factorial integrated intervention OQ-15
D16 Psilocybin produces large uncontrolled PTSD change (PMIDs: 40883964, 42533157) No randomized psilocybin PTSD trial exists A controlled comparison at all OQ-16
D17 A drug-only trial shows a PTSD effect (PMID 41706459) MDMA effects are measured only inside a therapy package (PMIDs: 33972795, 37709999) Factorial drug × therapy design in one population OQ-17
D18 Pre-trauma cohorts identify predisposing neural and fear-learning markers (PMIDs: 40024495, 41103636) Treatment selection uses none of them Prospective marker-stratified treatment assignment OQ-12
D19 Sequencing CBT-I before CPT helps (PMID 34265777) Integrating CBT-I with PE does not (PMID 40488726) Head-to-head test of sequence vs integration OQ-3
D20 Massed and telehealth delivery are non-inferior (PMIDs: 29362795, 26243685) Routine care still delivers weekly in-person courses with 38–51% dropout (PMID 41926191) Implementation trial of the non-inferior format as default OQ-1

Pooling control

GAD and PTSD are neighbours, not subsets. A mixed-anxiety trial or pooled anxiety-disorder effect does not answer a PTSD question unless a PTSD stratum is reported. Comorbid depression is cross-linked to the depression condition and measured separately.