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PTSD — Epidemiology and risk

TL;DR — Trauma exposure is common; PTSD is a conditional outcome whose probability depends on trauma type, cumulative exposure, sex/gender, prior mental disorder, childhood adversity and post-trauma social conditions. Estimates cannot be transported without the diagnostic system, time horizon, instrument and population. A child/adolescent meta-analysis estimated 15.9% (95% CI 11.5–21.5) after trauma, illustrating conditional risk rather than population prevalence (Alisic 2014, PMID 24785767). Mixed ‘anxiety disorder’ estimates must not be relabelled as PTSD.

Denominators

Lifetime prevalence among all residents, current prevalence, prevalence among trauma-exposed people and incidence after one event answer different questions. A 2026 state-of-the-science review places US lifetime prevalence at 6.1–8.3% and global prevalence at 3.9%, consistently higher in women and in military veterans (Flesaker 2026, PMID 42089634) — figures that are not interchangeable with the conditional risks below. Perinatal work illustrates the same split within one population: pooled prenatal PTSD prevalence was 3.3% (95% CI 2.44–4.54) and postpartum 4.0% (95% CI 2.77–5.71) in community samples, against 18.95% (95% CI 10.62–31.43) and 18.5% (95% CI 10.6–30.38) in high-risk groups, across 59 studies and 24,267 women (Yildiz 2017, PMID 27865585); the strongest correlates of birth-related PTSD were negative subjective birth experience (r=0.59), depression in pregnancy (r=0.51) and operative birth (r=0.48) across 50 studies and 21,429 women (Ayers 2016, PMID 26878223). Tables must preserve the denominator.

Trauma type

Interpersonal violence and sexual violence generally carry higher conditional risk than many accidents or disasters; repeated exposure and childhood adversity alter both dose and phenotype. Comparisons are confounded by age, sex, prior disorder and measurement (Yildiz 2017, PMID 27865585) (Ozer 2003, PMID 12555794).

Sex and gender

Higher female PTSD risk is consistent across many studies, but proposed explanations span exposure type, age, perceived threat, dissociation, social support and biological response; no single pathway explains the whole difference (Olff 2007, PMID 17338596).

Occupational populations

Military, first-responder and healthcare samples combine selection, repeated exposure and institution-specific help-seeking, and their prevalence figures belong to those populations. Pooling 18 studies of 30,878 ambulance personnel gave an estimated PTSD prevalence of 11%, alongside 15% for depression, 15% for anxiety and 27% for general psychological distress — a first-responder estimate, not a civilian one (Petrie 2018, PMID 29869691). Age-defined subpopulations behave differently again: PTSD in older adults raises distinct measurement and course questions (Pless Kaiser 2019, PMID 30422749), and geriatric US military veterans have their own reported disorder prevalences (Little 2018, PMID 29609900). Occupational and cohort context also shifts with the historical moment in which a population is studied (Jones 2019, PMID 31184277). None of these should be used as generic civilian prevalence estimates.

Risk versus cause

A predictor need not be specific to PTSD. Prior depression, generalized anxiety, substance use and social disadvantage may predict several outcomes. Cross-disorder predictors must be reported as such, while PTSD-specific strata remain separate (Carpenter 2018, PMID 29451967).

Course

Cross-sectional prevalence cannot distinguish delayed recognition, chronicity, remission and recurrence, and most risk-factor estimates are drawn from post-trauma samples in which vulnerability and consequence cannot be separated (Trickey 2012, PMID 22245560) (Ozer 2003, PMID 12555794). Prospective cohorts that measure candidate risk factors before trauma are the design that resolves this, and they remain uncommon: two examples are a pre-deployment fear-conditioning study in 643 male service members, in which poor pre-trauma discrimination between threat and safety signals predicted new-onset PTSD and slower pre-trauma extinction learning predicted symptom severity (Acheson 2025, PMID 41103636), and a 221-recruit police cohort scanned before trauma exposure, in which heightened dorsal amygdala response and amygdala–precuneus coupling during threat anticipation predicted subsequent symptom increase while lateral amygdala reactivity tracked trauma exposure itself rather than symptoms (de Voogd 2025, PMID 40024495). Both are occupational cohorts of predominantly male, pre-screened personnel, so they do not transport unchanged to civilian populations. A review of ambulance personnel illustrates how the same occupational groups are usually studied cross-sectionally instead (Petrie 2018, PMID 29869691).

Quantitative anchors

Measure Estimate Population/method Source
Trauma-exposed youth 15.9% (95% CI 11.5–21.5) 43 samples; n=3,563 (Alisic 2014, PMID 24785767)
CPTSD population range 1–8% Review; methods vary (Maercker 2022, PMID 35780794)
CPTSD clinical range up to 50% Mental-health facilities; referral enrichment (Maercker 2022, PMID 35780794)
Gender evidence higher risk in women Mechanisms and exposure distribution reviewed (Olff 2007, PMID 17338596)
US lifetime prevalence 6.1–8.3% Population estimate; review of survey data (Flesaker 2026, PMID 42089634)
Global prevalence 3.9% Population estimate; review (Flesaker 2026, PMID 42089634)
Ambulance personnel PTSD 11% 18 studies; n=30,878 pooled (Petrie 2018, PMID 29869691)
Prenatal PTSD, community 3.3% (95% CI 2.44–4.54) 59 studies; N=24,267 (Yildiz 2017, PMID 27865585)
Postpartum PTSD, community 4.0% (95% CI 2.77–5.71) Same review (Yildiz 2017, PMID 27865585)
Perinatal PTSD, high-risk groups 18.95% pregnancy; 18.5% postpartum Same review; referral-enriched (Yildiz 2017, PMID 27865585)
Birth-related PTSD correlates negative birth experience r=0.59; operative birth r=0.48 50 studies; n=21,429 (Ayers 2016, PMID 26878223)
Pre-trauma fear learning poor threat/safety discrimination predicts new-onset PTSD 643 male service members; pre/post deployment (Acheson 2025, PMID 41103636)
Pre-trauma amygdala response dorsal amygdala threat anticipation predicts symptom increase 221 police recruits; prospective fMRI (de Voogd 2025, PMID 40024495)

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
27865585 2017 The prevalence of posttraumatic stress disorder in pregnancy and after birth: A systematic review and meta-analysis. Synthesis: preserve included-population and certainty limits
26878223 2016 The aetiology of post-traumatic stress following childbirth: a meta-analysis and theoretical framework. Synthesis: preserve included-population and certainty limits
12555794 2003 Predictors of posttraumatic stress disorder and symptoms in adults: a meta-analysis. Synthesis: preserve included-population and certainty limits
22245560 2012 A meta-analysis of risk factors for post-traumatic stress disorder in children and adolescents. Synthesis: preserve included-population and certainty limits
29869691 2018 Prevalence of PTSD and common mental disorders amongst ambulance personnel: a systematic review and meta-analysis. Synthesis: preserve included-population and certainty limits
24785767 2014 Rates of post-traumatic stress disorder in trauma-exposed children and adolescents: meta-analysis. Synthesis: preserve included-population and certainty limits
17338596 2007 Gender differences in posttraumatic stress disorder. PTSD-specific record; inspect design and population
35780794 2022 Complex post-traumatic stress disorder. PTSD-specific record; inspect design and population
39324396 2024 Posttraumatic stress disorder (PTSD) prevalence: an umbrella review. Synthesis: preserve included-population and certainty limits
40570696 2025 Prevalence of Complex Post-Traumatic Stress Disorder (CPTSD): A Systematic Review and Meta-Analysis. Synthesis: preserve included-population and certainty limits
36825800 2024 Global Prevalence and Mental Health Outcomes of Intimate Partner Violence Among Women: A Systematic Review and Meta-Analysis. Synthesis: preserve included-population and certainty limits
31200992 2019 New WHO prevalence estimates of mental disorders in conflict settings: a systematic review and meta-analysis. Synthesis: preserve included-population and certainty limits
34498953 2021 Prevalence of post-traumatic stress disorder in the United States: a systematic literature review. Synthesis: preserve included-population and certainty limits
31520677 2019 Risk factors for posttraumatic stress disorder: An umbrella review of systematic reviews and meta-analyses. Synthesis: preserve included-population and certainty limits
38553144 2024 Mental and physical health morbidity among people in prisons: an umbrella review. Synthesis: preserve included-population and certainty limits
32956381 2020 The prevalence of mental illness in refugees and asylum seekers: A systematic review and meta-analysis. Synthesis: preserve included-population and certainty limits
25678565 2015 Editorial: Veterans' health. PTSD-specific record; inspect design and population
36341802 2023 The prevalence and risk factors of mental problems in medical students during COVID-19 pandemic: A systematic review and meta-analysis. Synthesis: preserve included-population and certainty limits
31313708 2019 Eating disorders and posttraumatic stress disorder. PTSD-specific record; inspect design and population
37236879 2023 Post-Traumatic Stress Disorder and Risk of Degenerative Synucleinopathies: Systematic Review and Meta-Analysis. Synthesis: preserve included-population and certainty limits
39434711 2024 Post-traumatic stress disorder in peacekeepers: a systematic literature review and meta-analysis. Synthesis: preserve included-population and certainty limits
37431310 2023 Post-traumatic stress disorder among LGBTQ people: a systematic review and meta-analysis. Synthesis: preserve included-population and certainty limits
38820681 2024 Post-Traumatic Stress-Disorder in Epilepsy: Meta-analysis of current evidence. Synthesis: preserve included-population and certainty limits
34242737 2022 Systematic Review and Meta-analysis: Prevalence of Posttraumatic Stress Disorder in Trauma-Exposed Preschool-Aged Children. Synthesis: preserve included-population and certainty limits
36352583 2022 Post-Traumatic Stress Disorder after Stroke: A Systematic Review. Synthesis: preserve included-population and certainty limits
30422749 2019 Posttraumatic Stress Disorder in Older Adults: A Conceptual Review. Synthesis: preserve included-population and certainty limits
31184277 2019 PTSD in an era of uncertainty and challenge. PTSD-specific record; inspect design and population
29609900 2018 Prevalence of Mental Health Disorders in Geriatric U.S. Military Veterans. PTSD-specific record; inspect design and population
29029837 2017 A review of current evidence regarding the ICD-11 proposals for diagnosing PTSD and complex PTSD. Synthesis: preserve included-population and certainty limits
42089634 2026 State of the Science: The epidemiology of posttraumatic stress disorder. Review of population estimates; not a new survey
41103636 2025 A prospective study of pre-trauma fear learning and extinction as risk factors for posttraumatic stress disorder. Male military cohort; occupational selection
40024495 2025 Amygdala Hyperactivity in Posttraumatic Stress Disorder: Disentangling Predisposing From Consequential Factors Using a Prospective Longitudinal Design. Police recruits; symptom scores, not diagnosis

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

  • What fraction of between-study prevalence variation is diagnostic system versus population and trauma composition? (Brewin 2017, PMID 29029837) (Yildiz 2017, PMID 27865585)
  • Which modifiable post-trauma factors have causal, not merely predictive, effects? (Ayers 2016, PMID 26878223)
  • How do repeated and cumulative exposures alter remission and recurrence trajectories? (Petrie 2018, PMID 29869691)

References

  1. Yildiz PD, et al. The prevalence of posttraumatic stress disorder in pregnancy and after birth: A systematic review and meta-analysis. J Affect Disord. 2017;208:634-645. PMID 27865585
  2. Ayers S, et al. The aetiology of post-traumatic stress following childbirth: a meta-analysis and theoretical framework. Psychol Med. 2016;46(6):1121-34. PMID 26878223
  3. Ozer EJ, et al. Predictors of posttraumatic stress disorder and symptoms in adults: a meta-analysis. Psychol Bull. 2003;129(1):52-73. PMID 12555794
  4. Trickey D, et al. A meta-analysis of risk factors for post-traumatic stress disorder in children and adolescents. Clin Psychol Rev. 2012;32(2):122-38. PMID 22245560
  5. Petrie K, et al. Prevalence of PTSD and common mental disorders amongst ambulance personnel: a systematic review and meta-analysis. Soc Psychiatry Psychiatr Epidemiol. 2018;53(9):897-909. PMID 29869691
  6. Alisic E, et al. Rates of post-traumatic stress disorder in trauma-exposed children and adolescents: meta-analysis. Br J Psychiatry. 2014;204:335-40. PMID 24785767
  7. Olff M, et al. Gender differences in posttraumatic stress disorder. Psychol Bull. 2007;133(2):183-204. PMID 17338596
  8. Maercker A, et al. Complex post-traumatic stress disorder. Lancet. 2022;400(10345):60-72. PMID 35780794
  9. Schincariol A, et al. Posttraumatic stress disorder (PTSD) prevalence: an umbrella review. Psychol Med. 2024;54(15):4021-4034. PMID 39324396
  10. Huynh PA, et al. Prevalence of Complex Post-Traumatic Stress Disorder (CPTSD): A Systematic Review and Meta-Analysis. Psychiatry Res. 2025;351:116586. PMID 40570696
  11. White SJ, et al. Global Prevalence and Mental Health Outcomes of Intimate Partner Violence Among Women: A Systematic Review and Meta-Analysis. Trauma Violence Abuse. 2024;25(1):494-511. PMID 36825800
  12. Charlson F, et al. New WHO prevalence estimates of mental disorders in conflict settings: a systematic review and meta-analysis. Lancet. 2019;394(10194):240-248. PMID 31200992
  13. Schein J, et al. Prevalence of post-traumatic stress disorder in the United States: a systematic literature review. Curr Med Res Opin. 2021;37(12):2151-2161. PMID 34498953
  14. Tortella-Feliu M, et al. Risk factors for posttraumatic stress disorder: An umbrella review of systematic reviews and meta-analyses. Neurosci Biobehav Rev. 2019;107:154-165. PMID 31520677
  15. Favril L, et al. Mental and physical health morbidity among people in prisons: an umbrella review. Lancet Public Health. 2024;9(4):e250-e260. PMID 38553144
  16. Blackmore R, et al. The prevalence of mental illness in refugees and asylum seekers: A systematic review and meta-analysis. PLoS Med. 2020;17(9):e1003337. PMID 32956381
  17. Galea S Editorial: Veterans' health. Am J Epidemiol. 2015;181(4):223-4. PMID 25678565
  18. Peng P, et al. The prevalence and risk factors of mental problems in medical students during COVID-19 pandemic: A systematic review and meta-analysis. J Affect Disord. 2023;321:167-181. PMID 36341802
  19. Rijkers C, et al. Eating disorders and posttraumatic stress disorder. Curr Opin Psychiatry. 2019;32(6):510-517. PMID 31313708
  20. Jones MB, et al. Post-Traumatic Stress Disorder and Risk of Degenerative Synucleinopathies: Systematic Review and Meta-Analysis. Am J Geriatr Psychiatry. 2023;31(11):978-990. PMID 37236879
  21. Carmona L, et al. Post-traumatic stress disorder in peacekeepers: a systematic literature review and meta-analysis. Eur J Psychotraumatol. 2024;15(1):2413735. PMID 39434711
  22. Marchi M, et al. Post-traumatic stress disorder among LGBTQ people: a systematic review and meta-analysis. Epidemiol Psychiatr Sci. 2023;32:e44. PMID 37431310
  23. Pepi C, et al. Post-Traumatic Stress-Disorder in Epilepsy: Meta-analysis of current evidence. Epilepsy Behav. 2024;157:109833. PMID 38820681
  24. Woolgar F, et al. Systematic Review and Meta-analysis: Prevalence of Posttraumatic Stress Disorder in Trauma-Exposed Preschool-Aged Children. J Am Acad Child Adolesc Psychiatry. 2022;61(3):366-377. PMID 34242737
  25. Tang WK, et al. Post-Traumatic Stress Disorder after Stroke: A Systematic Review. Neurol India. 2022;70(5):1887-1895. PMID 36352583
  26. Pless Kaiser A, et al. Posttraumatic Stress Disorder in Older Adults: A Conceptual Review. Clin Gerontol. 2019;42(4):359-376. PMID 30422749
  27. Jones E PTSD in an era of uncertainty and challenge. Int Rev Psychiatry. 2019;31(1):1-2. PMID 31184277
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