PTSD treatment dropout and nonresponse¶
TL;DR — Dropout and nonresponse are distinct: leaving treatment does not prove intolerance, and completing without adequate improvement is not dropout. A cross-disorder placebo-controlled CBT meta-analysis found PTSD-study dropout of 29.0% with CBT versus 17.2% with placebo, but that pooled paper included GAD, OCD, panic, social anxiety and acute stress disorder; only its PTSD stratum belongs here (Carpenter 2018, PMID 29451967). Routine-care estimates of 38–51% motivated a 916-veteran randomized CPT-versus-PE dropout analysis, which found dropout of 52.31% in PE against 45.77% in CPT, diverging after session 3 (Harper 2026, PMID 41926191). Trials should report timing, reasons, denominator and outcomes after dropout.
Definitions¶
Study dropout, treatment dropout, protocol noncompletion, loss to follow-up and missing outcome are separate events. Authors should define the last attended session and whether early responders who stopped are counted.
Why denominator matters¶
Per-protocol/completer effects answer what happened among completers; intention-to-treat estimates preserve randomization but still depend on missing-data assumptions. Neither alone measures delivered benefit.
Reasons¶
Scheduling, transport, childcare, work, relocation, cost, therapeutic mismatch, early improvement, symptom activation, adverse events and disengagement are not interchangeable, and trial reports rarely separate them: reviews of the PTSD evidence base and of CBT across disorders treat all-cause dropout as a single acceptability outcome rather than resolving its causes (Bisson 2021, PMID 34992739) (Cuijpers 2025, PMID 40238104). In a 157-RCT network and pairwise meta-analysis of 11,565 patients, all-cause dropout was the acceptability metric, and slightly more patients dropped out from TF-CBT than from non-trauma-focused interventions (RR 1.36, 95% CI 1.08–1.70, 22 comparisons), with no other between-intervention acceptability differences (Hoppen 2023, PMID 37141033).
Predictors¶
Baseline severity and demographics often show weak or inconsistent prediction. An individual-participant-data meta-analysis of 25 trauma-focused CBT trials (823 participants of 3,330 in 81 eligible studies) found 27% dropout overall, 23% among 581 civilians against 42% among 178 military personnel and veterans (RR 2.37 for military status), and a decreasing risk with advancing age (RR 0.98 per year) — but no strong pretreatment predictors beyond those (Wright 2024, PMID 39537555). A 19-study systematic review of veteran PTSD treatment retention likewise found only older age and higher treatment expectations associated with better retention at moderate quality of evidence; in five of six studies baseline PTSD severity was unrelated to retention, and more co-occurring psychiatric diagnoses were associated with better retention (Maglione 2022, PMID 34800059). Session-level change, alliance and avoidance sit closer to the event but are measured after randomization, so they carry post-randomization selection bias; in the CPT-versus-PE trial, slower symptom reduction predicted dropout in CPT but not in PE (Harper 2026, PMID 41926191).
Nonresponse¶
Response thresholds depend on measure and reliable-change rules. Some patients improve function without crossing a symptom threshold; others lose diagnosis but retain substantial burden.
Pooling warning¶
Mixed-anxiety attrition is not PTSD attrition. The Carpenter review is used only for its explicitly reported PTSD subgroup; its overall Hedges g=.56 is not presented as a PTSD effect (Carpenter 2018, PMID 29451967).
Design response¶
Pragmatic trials should collect minimal outcomes after discontinuation, competing reasons, treatment dose and patient choice; estimands should distinguish treatment-policy from hypothetical full-adherence effects.
Quantitative anchors¶
| Measure | Estimate | Population/method | Source |
|---|---|---|---|
| PTSD stratum in cross-disorder CBT review | 29.0% CBT vs 17.2% placebo | Do not report pooled anxiety effect as PTSD | (Carpenter 2018, PMID 29451967) |
| CPT vs PE | n=916 veterans | Randomized timing/predictor analysis | (Harper 2026, PMID 41926191) |
| Adult NMA | 90 trials; n=6,560 | Efficacy network; attrition affects certainty | (Mavranezouli 2020, PMID 32063234) |
| Exposure review | 65 articles; n=4,929 | Moderators are study-level | (McLean 2022, PMID 34954460) |
| CPT vs PE dropout | 45.77% vs 52.31%; separation after session 3 | n=916 US veterans | (Harper 2026, PMID 41926191) |
| TF-CBT dropout, IPD | 27% overall; 23% civilian vs 42% military (RR 2.37) | 25 pooled trials; n=823 | (Wright 2024, PMID 39537555) |
| TF-CBT vs non-TF acceptability | RR 1.36 (95% CI 1.08–1.70) | 157 RCTs; n=11,565; 22 comparisons | (Hoppen 2023, PMID 37141033) |
| Veteran retention predictors | older age, higher expectations (moderate QoE) | 19 studies in 25 publications | (Maglione 2022, PMID 34800059) |
Evidence ledger¶
The ledger lists the live-retrieved records used to bound this page. Inclusion does not make every record equally probative; design, population and comparator remain decisive.
| PMID | Year | Evidence contribution | Scope caution |
|---|---|---|---|
| 29451967 | 2018 | Cognitive behavioral therapy for anxiety and related disorders: A meta-analysis of randomized placebo-controlled trials. | Synthesis: preserve included-population and certainty limits |
| 41926191 | 2026 | Comparing dropout from cognitive processing therapy versus prolonged exposure: Results from a randomized clinical trial. | PTSD-specific record; inspect design and population |
| 40238104 | 2025 | Cognitive Behavior Therapy for Mental Disorders in Adults: A Unified Series of Meta-Analyses. | PTSD-specific record; inspect design and population |
| 34992739 | 2021 | Prevention and treatment of PTSD: the current evidence base. | PTSD-specific record; inspect design and population |
| 38173121 | 2024 | EMDR v. other psychological therapies for PTSD: a systematic review and individual participant data meta-analysis. | Synthesis: preserve included-population and certainty limits |
| 24338345 | 2013 | Psychological therapies for chronic post-traumatic stress disorder (PTSD) in adults. | PTSD-specific record; inspect design and population |
| 32813696 | 2020 | Psychological and pharmacological interventions for posttraumatic stress disorder and comorbid mental health problems following complex traumatic events: Systematic review and component network meta-analysis. | Synthesis: preserve included-population and certainty limits |
| 41004137 | 2025 | PTSD and complex PTSD, current treatments and debates: a review of reviews. | Synthesis: preserve included-population and certainty limits |
| 38652057 | 2024 | State of the Science: Prolonged exposure therapy for the treatment of posttraumatic stress disorder. | PTSD-specific record; inspect design and population |
| 29252162 | 2018 | Mindfulness-based treatments for posttraumatic stress disorder: a review of the treatment literature and neurobiological evidence. | Synthesis: preserve included-population and certainty limits |
| 38713560 | 2024 | [MDMA-assisted therapy for PTSD]. | PTSD-specific record; inspect design and population |
| 36044299 | 2022 | Psychotherapeutic interventions for childhood posttraumatic stress disorder: an update. | PTSD-specific record; inspect design and population |
| 34477098 | 2021 | Comparing treatments for post-traumatic stress disorder - a systematic review. | Synthesis: preserve included-population and certainty limits |
| 38814110 | 2024 | Interpersonal Psychotherapy for Posttraumatic Stress Disorder: A Critical Review of the Evidence. | Synthesis: preserve included-population and certainty limits |
| 29169664 | 2018 | Long-term efficacy of psychotherapy for posttraumatic stress disorder: A meta-analysis of randomized controlled trials. | Synthesis: preserve included-population and certainty limits |
| 31797352 | 2019 | Couple and family therapies for post-traumatic stress disorder (PTSD). | PTSD-specific record; inspect design and population |
| 12729679 | 2003 | Posttraumatic stress disorder following medical illness and treatment. | PTSD-specific record; inspect design and population |
| 36595460 | 2024 | A systematic review evaluating PTSD treatment effects on intermediate phenotypes of PTSD. | Synthesis: preserve included-population and certainty limits |
| 35700643 | 2022 | Review of potential psychedelic treatments for PTSD. | Synthesis: preserve included-population and certainty limits |
| 15846661 | 2005 | Psychological treatment of post-traumatic stress disorder (PTSD). | PTSD-specific record; inspect design and population |
| 38523454 | 2024 | Systematic Review of Dispositional Mindfulness and Posttraumatic Stress Disorder Symptomology: A Targeted Examination of Avoidance. | Synthesis: preserve included-population and certainty limits |
| 17636720 | 2007 | Psychological treatment of post-traumatic stress disorder (PTSD). | PTSD-specific record; inspect design and population |
| 34582228 | 2022 | Treatment dropout among veterans and their families: Quantitative and qualitative findings. | PTSD-specific record; inspect design and population |
| 32063234 | 2020 | Psychological treatments for post-traumatic stress disorder in adults: a network meta-analysis. | Synthesis: preserve included-population and certainty limits |
| 32284821 | 2020 | Psychological therapies for post-traumatic stress disorder in adults: systematic review and meta-analysis. | Synthesis: preserve included-population and certainty limits |
| 34954460 | 2022 | Exposure therapy for PTSD: A meta-analysis. | Synthesis: preserve included-population and certainty limits |
| 32074319 | 2020 | Drivers of Preference for Evidence-Based PTSD Treatment: A Qualitative Assessment. | PTSD-specific qualitative evidence; preference is not efficacy |
| 38590124 | 2024 | Cognitive-behavioural conjoint therapy versus prolonged exposure for PTSD in military service members and veterans: results and lessons from a randomized controlled trial. | PTSD-specific record; inspect design and population |
| 39537555 | 2024 | Predictors of study dropout in cognitive-behavioural therapy with a trauma focus for post-traumatic stress disorder in adults: An individual participant data meta-analysis. | IPD; only 823 of 3,330 eligible participants pooled |
| 34800059 | 2022 | Effect of patient characteristics on posttraumatic stress disorder treatment retention among veterans: A systematic review. | Narrative synthesis; definitions of dropout varied |
| 37141033 | 2023 | The efficacy and acceptability of psychological interventions for adult PTSD: A network and pairwise meta-analysis of randomized controlled trials. | Synthesis: acceptability measured as all-cause dropout |
Interpretation guardrails¶
- Trauma exposure, post-traumatic symptoms, acute stress disorder, DSM-5 PTSD, ICD-11 PTSD and ICD-11 complex PTSD are not interchangeable populations.
- A mixed-anxiety or transdiagnostic estimate is labelled as such; only a source’s PTSD stratum can be treated as a PTSD effect.
- Comorbid depression is measured separately and cross-linked to the depression condition; it is not absorbed into PTSD.
- Waitlist, treatment-as-usual, attention control and active treatment answer different causal questions.
- Registration, statistical significance and diagnostic loss do not respectively prove completion, clinical importance or functional recovery.
- This page synthesizes research and does not provide individual medical advice.
Minimum extraction frame for studies on this topic¶
| Field | What must be retained | Why it changes interpretation |
|---|---|---|
| Diagnostic system | DSM version, ICD version, full/subthreshold | Case mix is not interchangeable |
| Diagnostic method | Structured interview, clinician judgment, self-report cutoff | Screening is not diagnosis |
| Index trauma | Type, timing, repetition, direct/indirect/occupational | Conditional risk and phenotype differ |
| Population | Civilian, veteran, refugee, child/adolescent, mixed | Transportability is empirical |
| Baseline severity | Mean, SD, range and exclusion threshold | Ceiling and floor effects alter change |
| CPTSD status | ITQ/ICD-11 definition and DSO score | Complexity cannot be inferred from trauma count |
| Comorbidity | Depression, GAD, SUD, pain, TBI measured separately | Shared symptoms can distort effects |
| Comparator | Waitlist, usual care, attention, active treatment | The estimand changes with comparator |
| Treatment dose | Sessions offered/attended, duration, homework | Assignment is not exposure |
| Outcome | Symptoms, diagnosis, response, function, sleep | Outcomes are not interchangeable |
| Time point | End point and prespecified follow-up windows | Acute benefit may not persist |
| Missing data | Denominator, reasons, imputation and estimand | Attrition can bias rank and magnitude |
| Adverse events | Definitions, ascertainment and arm-level counts | Absence of reporting is not absence of harm |
| Therapist/context | Training, fidelity, allegiance, setting | Delivery is part of the intervention |
| Funding/conflicts | Sponsor role and analytic independence | Especially material for proprietary packages |
Claims this page does not make¶
- It does not infer PTSD from trauma exposure alone.
- It does not treat a self-report cutoff as equivalent to a structured diagnosis.
- It does not convert a pooled anxiety-disorder effect into a PTSD effect.
- It does not convert a depression outcome in a comorbid sample into a PTSD outcome.
- It does not infer superiority from a statistically significant within-group change.
- It does not infer equivalence from a non-significant between-group test.
- It does not infer effectiveness from trial registration or mechanistic plausibility.
- It does not assume military, civilian, refugee and pediatric estimates transport unchanged.
- It does not average conflicting estimates that use different definitions.
- It does not treat lack of adverse-event reporting as evidence of safety.
Evidence-updating triggers¶
| Trigger | Required response |
|---|---|
| New diagnostic revision | Recalculate which populations prior estimates represent |
| New head-to-head RCT | Compare against active treatment, not only waitlist |
| New individual-participant synthesis | Revisit effect modifiers and transportability |
| Registry status change | Verify results and linked publication before changing conclusions |
| Guideline update | Separate evidence review from panel recommendation |
| Regulatory decision | Record decision date and source; do not infer from efficacy papers |
| Safety signal | Re-extract denominator, ascertainment and exposure time by arm |
| Contradictory replication | Display estimates side by side; do not average definitions |
Evidence updates should preserve the prior estimate and explain why the new study changes—or does not change—the inference.
Open questions¶
- Which modifiable early-session signals predict avoidable dropout rather than administrative loss? (Harper 2026, PMID 41926191)
- How should retention-adjusted benefit combine symptom change and treatment burden? (Mavranezouli 2020, PMID 32063234)
- Do preference-matched assignments improve completion without sacrificing outcomes? (Etingen 2020, PMID 32074319)
Related pages¶
- comparative-psychotherapy-evidence — efficacy rankings need attrition context.
- patient-experience-and-advocacy — reasons and preferences.
- red-flags-and-safety-concerns — adverse events and symptom activation.
- military-and-veteran-populations — largest direct dropout trial.
References¶
- Carpenter JK, et al. Cognitive behavioral therapy for anxiety and related disorders: A meta-analysis of randomized placebo-controlled trials. Depress Anxiety. 2018;35(6):502-514. PMID 29451967
- Harper KL, et al. Comparing dropout from cognitive processing therapy versus prolonged exposure: Results from a randomized clinical trial. J Consult Clin Psychol. 2026;94(3):140-150. PMID 41926191
- Cuijpers P, et al. Cognitive Behavior Therapy for Mental Disorders in Adults: A Unified Series of Meta-Analyses. JAMA Psychiatry. 2025;82(6):563-571. PMID 40238104
- Bisson JI, et al. Prevention and treatment of PTSD: the current evidence base. Eur J Psychotraumatol. 2021;12(1):1824381. PMID 34992739
- Wright SL, et al. EMDR v. other psychological therapies for PTSD: a systematic review and individual participant data meta-analysis. Psychol Med. 2024;54(8):1580-1588. PMID 38173121
- Bisson JI, et al. Psychological therapies for chronic post-traumatic stress disorder (PTSD) in adults. Cochrane Database Syst Rev. 2013;2013(12):CD003388. PMID 24338345
- Coventry PA, et al. Psychological and pharmacological interventions for posttraumatic stress disorder and comorbid mental health problems following complex traumatic events: Systematic review and component network meta-analysis. PLoS Med. 2020;17(8):e1003262. PMID 32813696
- Billings J, et al. PTSD and complex PTSD, current treatments and debates: a review of reviews. Br Med Bull. 2025;156(1):ldaf015. PMID 41004137
- McLean CP, et al. State of the Science: Prolonged exposure therapy for the treatment of posttraumatic stress disorder. J Trauma Stress. 2024;37(4):535-550. PMID 38652057
- Boyd JE, et al. Mindfulness-based treatments for posttraumatic stress disorder: a review of the treatment literature and neurobiological evidence. J Psychiatry Neurosci. 2018;43(1):7-25. PMID 29252162
- Thorarinsdottir H, et al. [MDMA-assisted therapy for PTSD]. Laeknabladid. 2024;110(5):254-261. PMID 38713560
- Rossouw J, et al. Psychotherapeutic interventions for childhood posttraumatic stress disorder: an update. Curr Opin Psychiatry. 2022;35(6):417-424. PMID 36044299
- Storm MP, et al. Comparing treatments for post-traumatic stress disorder - a systematic review. Dan Med J. 2021;68(9):A09200643. PMID 34477098
- Markowitz JC Interpersonal Psychotherapy for Posttraumatic Stress Disorder: A Critical Review of the Evidence. J Clin Psychiatry. 2024;85(2):23nr15172. PMID 38814110
- Kline AC, et al. Long-term efficacy of psychotherapy for posttraumatic stress disorder: A meta-analysis of randomized controlled trials. Clin Psychol Rev. 2018;59:30-40. PMID 29169664
- Suomi A, et al. Couple and family therapies for post-traumatic stress disorder (PTSD). Cochrane Database Syst Rev. 2019;12(12):CD011257. PMID 31797352
- Tedstone JE, et al. Posttraumatic stress disorder following medical illness and treatment. Clin Psychol Rev. 2003;23(3):409-48. PMID 12729679
- Palmisano AN, et al. A systematic review evaluating PTSD treatment effects on intermediate phenotypes of PTSD. Psychol Trauma. 2024;16(5):768-783. PMID 36595460
- Henner RL, et al. Review of potential psychedelic treatments for PTSD. J Neurol Sci. 2022;439:120302. PMID 35700643
- Bisson J, et al. Psychological treatment of post-traumatic stress disorder (PTSD). Cochrane Database Syst Rev. 2005;(2):CD003388. PMID 15846661
- Sylvia AM, et al. Systematic Review of Dispositional Mindfulness and Posttraumatic Stress Disorder Symptomology: A Targeted Examination of Avoidance. Trauma Violence Abuse. 2024;25(4):2622-2637. PMID 38523454
- Bisson J, et al. Psychological treatment of post-traumatic stress disorder (PTSD). Cochrane Database Syst Rev. 2007;(3):CD003388. PMID 17636720
- Amsalem D, et al. Treatment dropout among veterans and their families: Quantitative and qualitative findings. Psychol Trauma. 2022;14(4):578-586. PMID 34582228
- Mavranezouli I, et al. Psychological treatments for post-traumatic stress disorder in adults: a network meta-analysis. Psychol Med. 2020;50(4):542-555. PMID 32063234
- Lewis C, et al. Psychological therapies for post-traumatic stress disorder in adults: systematic review and meta-analysis. Eur J Psychotraumatol. 2020;11(1):1729633. PMID 32284821
- McLean CP, et al. Exposure therapy for PTSD: A meta-analysis. Clin Psychol Rev. 2022;91:102115. PMID 34954460
- Etingen B, et al. Drivers of Preference for Evidence-Based PTSD Treatment: A Qualitative Assessment. Mil Med. 2020;185(Suppl 1):303-310. PMID 32074319
- Monson CM, et al. Cognitive-behavioural conjoint therapy versus prolonged exposure for PTSD in military service members and veterans: results and lessons from a randomized controlled trial. Eur J Psychotraumatol. 2024;15(1):2330305. PMID 38590124
- Wright S, et al. Predictors of study dropout in cognitive-behavioural therapy with a trauma focus for post-traumatic stress disorder in adults: An individual participant data meta-analysis. BMJ Ment Health. 2024;27(1):e301159. PMID 39537555
- Maglione MA, et al. Effect of patient characteristics on posttraumatic stress disorder treatment retention among veterans: A systematic review. J Trauma Stress. 2022;35(2):718-728. PMID 34800059
- Hoppen TH, et al. The efficacy and acceptability of psychological interventions for adult PTSD: A network and pairwise meta-analysis of randomized controlled trials. J Consult Clin Psychol. 2023;91(8):445-461. PMID 37141033