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Frontiers in psychology2026; 17; 1768001; doi: 10.3389/fpsyg.2026.1768001

Horsepower: equine-assisted interventions are associated with reduced PTSD symptoms, improved sleep quality, and quality of life in military veterans with treatment-resistant PTSD.

Abstract: Military veterans are at an elevated risk of developing posttraumatic stress disorder (PTSD), while first-line trauma-focused treatments are less effective in this population. This highlights the need for novel, evidence-based complementary interventions for military veterans with treatment-resistant PTSD. Although equine-assisted interventions (EAIs) are increasingly popular and appear promising, many studies suffer from methodological issues. Therefore, further research incorporating both psychometric and physiological parameters is warranted. Unassigned: Nine consecutive groups of eight veterans ( = 72; 58 men and 14 women) participated in this study. Due to a dropout rate of 8.33% and the exclusion of 11.11% of participants for missing more than two sessions, 58 veterans were included in the dataset. All participants had a prior PTSD diagnosis and/or a score >31 on the PTSD Checklist for DSM-5 (PCL-5) questionnaire at intake and had previous evidence-based treatment but continued to experience symptoms. The program consisted of 12 weekly non-trauma-focused group sessions and one follow-up session (week 24), all lasting from 10:00 to 15:00. Measurements were performed during baseline conditions (B), a 20-min free activity (F) focused on relaxation and social affiliative contact with the horse, and a 30-min directed activity (D) involving caretaking, groundwork, and riding. Unassigned: Psychometric questionnaires demonstrated a significant decrease in PTSD symptoms (PCL-5), an improvement in sleep quality (Pittsburgh Sleep Quality Index [PSQI]), and an improvement in quality of life (EuroQol 5-Dimension 5-Level questionnaire [EQ-5D-5L]), with effects persisting at least until the 3-month follow-up session. No significant differences in heart rate (HR) or heart rate variability (HRV) were observed between pre- and post-intervention. However, during EAI sessions, patterns consistent with physiological adaptation were observed, as HR decreased and HRV increased after the first week during free interactions with the horse. Unassigned: In conclusion, the EAI program was associated with long-term effects on PTSD, sleep quality, and quality of life in veterans with treatment-resistant PTSD. No structural changes in physiological parameters were found, only evidence for successful adaptation to acute stress during EAI sessions. We hypothesize that adaptation to physiological arousal during acute stress may represent a possible working mechanism of EAI.
Copyright © 2026 Kapteijn, Vermetten, Rodenburg and Endenburg.
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Publication Date: 2026-06-09 PubMed ID: 42344989PubMed Central: PMC13286912DOI: 10.3389/fpsyg.2026.1768001Google Scholar: Lookup
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Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

Overview

  • This study investigated the effects of equine-assisted interventions (EAIs) on military veterans with treatment-resistant posttraumatic stress disorder (PTSD).
  • The research found that participation in EAIs was linked to reduced PTSD symptoms, better sleep quality, and improved quality of life, with benefits lasting at least three months after the program.

Background and Rationale

  • Military veterans face a higher risk of developing PTSD, a mental health condition triggered by traumatic experiences.
  • Standard first-line trauma-focused treatments often have limited effectiveness in veterans with treatment-resistant PTSD.
  • There is a growing interest in alternative therapies, such as equine-assisted interventions (EAIs), which involve activities with horses and may support mental health recovery.
  • Previous studies on EAIs were often methodologically weak, necessitating more rigorous research incorporating both psychological assessments and physiological measurements.

Study Design and Participants

  • The study included 72 military veterans divided into nine groups of eight participants (58 men, 14 women).
  • Due to a dropout rate and exclusions for missed sessions, data from 58 veterans were analyzed.
  • All participants had confirmed PTSD diagnoses or high PTSD symptom scores (PCL-5 >31) and had undergone prior evidence-based PTSD treatments but still experienced symptoms.
  • The intervention consisted of 12 weekly group sessions plus a follow-up session at week 24, each lasting five hours (10:00–15:00).

Intervention Details

  • Each session featured three main conditions for measurement:
    • Baseline conditions (B) for comparison.
    • A 20-minute free activity (F) encouraging relaxation and social contact with the horse.
    • A 30-minute directed activity (D) involving caretaking, groundwork exercises, and riding the horse.

Psychometric Outcomes

  • PTSD symptom severity was assessed with the PTSD Checklist for DSM-5 (PCL-5).
  • Sleep quality was measured using the Pittsburgh Sleep Quality Index (PSQI).
  • Quality of life was measured by the EuroQol 5-Dimension 5-Level questionnaire (EQ-5D-5L).
  • Results indicated:
    • Significant decreases in PTSD symptoms after the intervention.
    • Improvements in sleep quality.
    • Enhanced quality of life ratings.
    • These psychological benefits persisted through the 3-month follow-up session.

Physiological Measurements

  • Heart rate (HR) and heart rate variability (HRV) were measured to monitor autonomic nervous system function and stress adaptation.
  • No significant long-term changes in baseline HR or HRV were found pre- versus post-intervention.
  • However, during the EAI sessions:
    • Heart rate tended to decrease, and HRV increased over time during free interactions with horses.
    • These changes suggest improved physiological regulation and adaptation to acute stress during the sessions.

Conclusions and Hypotheses

  • The EAI program demonstrated long-lasting beneficial effects on PTSD symptoms, sleep quality, and quality of life for veterans with treatment-resistant PTSD.
  • While no structural, lasting physiological changes were detected outside sessions, physiological adaptation during the acute stress of sessions was evident.
  • The authors propose that one possible mechanism behind EAI’s effectiveness is improving the veterans’ ability to adapt to physiological arousal and stress in the moment.
  • This stress adaptation might help break the cycle of chronic PTSD symptoms by promoting emotional regulation and resilience.

Implications

  • EAIs may offer an effective, complementary therapy for military veterans who do not fully respond to traditional PTSD treatments.
  • Improving sleep and quality of life are critical outcomes tied to overall veterans’ well-being.
  • Future research should continue to explore physiological markers and refine EAI protocols for this population.

Cite This Article

APA
Kapteijn CM, Vermetten E, Rodenburg TB, Endenburg N. (2026). Horsepower: equine-assisted interventions are associated with reduced PTSD symptoms, improved sleep quality, and quality of life in military veterans with treatment-resistant PTSD. Front Psychol, 17, 1768001. https://doi.org/10.3389/fpsyg.2026.1768001

Publication

Frontiers in psychology
ISSN: 1664-1078
NlmUniqueID: 101550902
Country: Switzerland
Language: English
Volume: 17
Pages: 1768001
PII: 1768001

Researcher Affiliations

Kapteijn, Chantal M
  • Animals in Science and Society, Department of Population Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands.
Vermetten, Eric
  • Department of Psychiatry, Leiden University Medical Centre, Leiden, Netherlands.
Rodenburg, T Bas
  • Animals in Science and Society, Department of Population Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands.
Endenburg, Nienke
  • Animals in Science and Society, Department of Population Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands.

Conflict of Interest Statement

The author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

References

This article includes 116 references
  1. Adams C, Arratoon C, Boucher J, Cartier G, Chalmers D, Dell C A. The helping horse: how equine assisted learning contributes to the wellbeing of first nations youth in treatment for volatile substance misuse. Human-Animal Inter. Bull 3, 52–75.
    doi: 10.1079/hai.2015.0005pmc: PMC4716821pubmed: 26793794google scholar: lookup
  2. Alcantara J M A, Plaza-Florido A, Amaro-Gahete F J, Acosta F M, Migueles J H, Molina-Garcia P. Impact of using different levels of threshold-based artefact correction on the quantification of heart rate variability in three independent human cohorts. J. Clin. Med. 9:325.
    doi: 10.3390/jcm9020325pmc: PMC7074236pubmed: 31979367google scholar: lookup
  3. Aranda C, de la Cruz B, Naranjo C. Effects of different automatic filters on the analysis of heart rate variability with Kubios HRV software. Arch. Med. Deporte 34, 196–200.
  4. Armour C, Tsai J, Durham T A, Charak R, Biehn T L, Elhai J D. Dimensional structure of DSM-5 posttraumatic stress symptoms: support for a hybrid anhedonia and externalizing behaviors model. J. Psychiatr. Res. 61, 106–113.
    doi: 10.1016/j.jpsychires.2014.10.012pubmed: 25479765google scholar: lookup
  5. Arnon S, Fisher P W, Pickover A, Lowell A, Turner J B, Hilburn A. Equine-assisted therapy for veterans with PTSD: manual development and preliminary findings. Mil. Med. 185, e557–e564.
    doi: 10.1093/milmed/usz444pmc: PMC7282489pubmed: 32034416google scholar: lookup
  6. Asnaani A, Reddy M K, Shea M T. The impact of PTSD symptoms on physical and mental health functioning in returning veterans. J. Anxiety Disord. 28, 310–317.
    doi: 10.1016/j.janxdis.2014.01.005pubmed: 24647406google scholar: lookup
  7. American Psychiatric Association. Diagnostic and Statistical Manual of mental Disorders: DSM-5. .
  8. Bachi K, Terkel J, Teichman M. Equine-facilitated psychotherapy for at-risk adolescents: the influence on self-image, self-control and trust. Clin. Child Psychol. Psychiatry 17, 298–312.
    doi: 10.1177/1359104511404177pubmed: 21757481google scholar: lookup
  9. Baevsky R M, Chernikova A G. Heart rate variability analysis: physiological foundations and main methods [review]. Cardiometry 10, 66–76.
    doi: 10.12710/cardiometry.2017.6676google scholar: lookup
  10. Bisson J I, Ehlers A, Matthews R, Pilling S, Richards D, Turner S. Psychological treatments for chronic post-traumatic stress disorder: systematic review and meta-analysis. Br. J. Psychiatry 190, 97–104.
    doi: 10.1192/bjp.bp.106.021402pubmed: 17267924google scholar: lookup
  11. Bisson J I, Roberts N P, Andrew M, Cooper R, Lewis C. Psychological therapies for chronic post-traumatic stress disorder (PTSD) in adults. Cochrane Database Syst. Rev. 2013:CD003388.
    doi: 10.1002/14651858.CD003388.pub4pmc: PMC6991463pubmed: 24338345google scholar: lookup
  12. Blanchard B E, Johnson M, Campbell S B, Reed D E, Chen S, Heagerty P J. Minimal important difference metrics and test-retest reliability of the PTSD checklist for DSM-5 with a primary care sample. J. Trauma. Stress. 36, 1102–1114.
    doi: 10.1002/jts.22975pmc: PMC10754254pubmed: 37845820google scholar: lookup
  13. Blevins C A, Weathers F W, Davis M T, Witte T K, Domino J L. The posttraumatic stress disorder checklist for DSM-5 (PCL-5): development and initial psychometric evaluation. J. Trauma. Stress. 28, 489–498.
    doi: 10.1002/jts.22059pubmed: 26606250google scholar: lookup
  14. Boss L, Branson S, Hagan H, Krause-Parello C. A systematic review of equine-assisted interventions in military veterans diagnosed with PTSD. J. Veterans Stud. 5, 23–33.
    doi: 10.21061/jvs.v5i1.134google scholar: lookup
  15. Bovin M J, Marx B P, Weathers F W, Gallagher M W, Rodriguez P, Schnurr P P. Psychometric properties of the PTSD checklist for diagnostic and statistical manual of mental disorders-fifth edition (PCL-5) in veterans. Psychol. Assess. 28, 1379–1391.
    doi: 10.1037/pas0000254pubmed: 26653052google scholar: lookup
  16. Bradley R, Greene J, Russ E, Dutra L, Westen D. A multidimensional Meta-analysis of psychotherapy for PTSD. Am. J. Psychiatry 162, 214–227.
    doi: 10.1176/appi.ajp.162.2.214pubmed: 15677582google scholar: lookup
  17. Burnham K P, Anderson D R. Multimodel Inference. Sociol. Methods Res. 33, 261–304.
    doi: 10.1177/0049124104268644google scholar: lookup
  18. Burton L E, Qeadan F, Burge M R. Efficacy of equine-assisted psychotherapy in veterans with posttraumatic stress disorder. J. Integr. Med. 17, 14–19.
    doi: 10.1016/j.joim.2018.11.001pubmed: 30497951google scholar: lookup
  19. Buysse D J, Reynolds C F, Monk T H, Berman S R, Kupfer D J. The Pittsburgh sleep quality index: a new instrument for psychiatric practice and research. Psychiatry Res. 28, 193–213.
    pubmed: 2748771
  20. Cao-Noya J A, Canovas C, Benuto L T. The use of biomarkers as measures of PTSD treatment efficacy and predictors of treatment outcomes: A systematic review. Clin. Psychol. Rev. 118:102579.
    doi: 10.1016/j.cpr.2025.102579pubmed: 40179593google scholar: lookup
  21. Carpenter A S, Andrykowski M A. Psychometric evaluation of the Pittsburgh sleep quality index. J. Psychosom. Res. 45, 5–13.
    pubmed: 9720850
  22. Castaldo R, Melillo P, Bracale U, Caserta M, Triassi M, Pecchia L. Acute mental stress assessment via short term HRV analysis in healthy adults: A systematic review with meta-analysis. Biomed. Signal Process. Control 18, 370–377.
    doi: 10.1016/j.bspc.2015.02.012google scholar: lookup
  23. Chan Y H. Biostatistics 301A. Repeated measurement analysis (mixed models). Singap. Med. J. 45, 456–461.
    pubmed: 15455165
  24. Charney M E, Hellberg S N, Bui E, Simon N M. Evidenced-based treatment of posttraumatic stress disorder: an updated review of validated psychotherapeutic and pharmacological approaches. Harv. Rev. Psychiatry 26, 99–115.
    doi: 10.1097/HRP.0000000000000186pubmed: 29734225google scholar: lookup
  25. Cheng L J, Chen L A, Cheng J Y, Herdman M, Luo N. Systematic review reveals that EQ-5D minimally important differences vary with treatment type and may decrease with increasing baseline score. J. Clin. Epidemiol. 174:111487.
    doi: 10.1016/j.jclinepi.2024.111487pubmed: 39084578google scholar: lookup
  26. Coventry P A, Meader N, Melton H, Temple M, Dale H, Wright K. 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. 17:e1003262.
    doi: 10.1371/journal.pmed.1003262pmc: PMC7446790pubmed: 32813696google scholar: lookup
  27. Creamer M, Forbes D. Treatment of posttraumatic stress disorder in military and veteran populations. Psychother. Theory Res. Pract. Train. 41, 388–398.
    doi: 10.1037/0033-3204.41.4.388google scholar: lookup
  28. Dams J, Rimane E, Steil R, Renneberg B, Rosner R, Konig H H. Health-related quality of life and costs of posttraumatic stress disorder in adolescents and Young adults in Germany. Front. Psych. 11:697.
    doi: 10.3389/fpsyt.2020.00697pmc: PMC7373788pubmed: 32760304google scholar: lookup
  29. Dams J, Rimane E, Steil R, Renneberg B, Rosner R, Konig H H. Reliability, validity and responsiveness of the EQ-5D-5L in assessing and valuing health status in adolescents and Young adults with posttraumatic stress disorder: a randomized Controlled Trail. Psychiatry Q. 92, 459–471.
    doi: 10.1007/s11126-020-09814-6pmc: PMC8110499pubmed: 32803473google scholar: lookup
  30. De Santis M, Contalbrigo L, Borgi M, Cirulli F, Luzi F, Redaelli V. Equine assisted interventions (EAIs): methodological considerations for stress assessment in horses. Vet Sci 4:Article 44.
    doi: 10.3390/vetsci4030044pmc: PMC5644660pubmed: 29056702google scholar: lookup
  31. Delaney PA, Brodie DA. Effects of short-term Psyhcological stress on the time and Frequence domains of heart-rate variability.. Percept. Mot. Skills 91, 515–524.
    doi: 10.2466/pms.2000.91.2.515pubmed: 11065312google scholar: lookup
  32. Dennis PA, Dedert EA, Van Voorhees EE, Watkins LL, Hayano J, Calhoun PS. Examining the crux of autonomic dysfunction in PTSD: whether chronic or situational distress underlies elevated heart rate and attenuated heart-rate variability.. Psychosom. Med. 78, 805–809.
    doi: 10.1097/PSY.0000000000000326pmc: PMC5003742pubmed: 27057817google scholar: lookup
  33. Dennis PA, Watkins LL, Calhoun PS, Oddone A, Sherwood A, Dennis MF. Posttraumatic stress, heart rate variability, and the mediating role of behavioral health risks.. Psychosom. Med. 76, 629–637.
    doi: 10.1097/PSY.0000000000000110pmc: PMC4197067pubmed: 25264973google scholar: lookup
  34. Dobbs WC, Fedewa MV, MacDonald HV, Holmes CJ, Cicone ZS, Plews DJ. The accuracy of acquiring heart rate variability from portable devices: A systematic review and Meta-analysis.. Sports Med. 49, 417–435.
    doi: 10.1007/s40279-019-01061-5pubmed: 30706234google scholar: lookup
  35. Duricki DA, Soleman S, Moon LD. Analysis of longitudinal data from animals with missing values using SPSS.. Nat. Protoc. 11, 1112–1129.
    doi: 10.1038/nprot.2016.048pmc: PMC5582138pubmed: 27196723google scholar: lookup
  36. Edwards-Stewart A, Smolenski DJ, Bush NE, Cyr BA, Beech EH, Skopp NA. Posttraumatic stress disorder treatment dropout among military and veteran populations: A systematic review and Meta-analysis.. J. Trauma. Stress. 34, 808–818.
    doi: 10.1002/jts.22653pubmed: 33524199google scholar: lookup
  37. Evenson KR, Wen F, Herring AH, Di C, LaMonte MJ, Tinker LF. Calibrating physical activity intensity for hip-worn accelerometry in women age 60 to 91 years: the Women's Health Initiative OPACH calibration study.. Prev. Med. Rep. 2, 750–756.
    doi: 10.1016/j.pmedr.2015.08.021pmc: PMC4625400pubmed: 26527313google scholar: lookup
  38. Feng YS, Kohlmann T, Janssen MF, Buchholz I. Psychometric properties of the EQ-5D-5L: a systematic review of the literature.. Qual. Life Res. 30, 647–673.
    doi: 10.1007/s11136-020-02688-ypmc: PMC7952346pubmed: 33284428google scholar: lookup
  39. Fisher PW, Lazarov A, Lowell A, Arnon S, Turner JB, Bergman M. Equine-assisted therapy for posttraumatic stress disorder among military veterans: an open trial.. J. Clin. Psychiatry 82:21m14005.
    doi: 10.4088/JCP.21m14005pubmed: 34464523google scholar: lookup
  40. Fonzo GA, Federchenco V, Lara A. Predicting and managing treatment non-response in posttraumatic stress disorder.. Curr. Treat. Options Psychiatry 7, 70–87.
    doi: 10.1007/s40501-020-00203-1pmc: PMC7748158pubmed: 33344106google scholar: lookup
  41. Forkus SR, Raudales AM, Rafiuddin HS, Weiss NH, Messman BA, Contractor AA. The posttraumatic stress disorder (PTSD) checklist for DSM-5: A systematic review of existing psychometric evidence.. Clin. Psychol. 30, 110–121.
    doi: 10.1037/cps0000111pmc: PMC10292741pubmed: 37378352google scholar: lookup
  42. Euroqol Research Foundation. EQ-5D-5L Userguide. .
  43. Galovski TE, Monson C, Bruce SE, Resick PA. Does cognitive-behavioral therapy for PTSD improve perceived health and sleep impairment?. J. Trauma. Stress. 22, 197–204.
    doi: 10.1002/jts.20418pmc: PMC2765684pubmed: 19466746google scholar: lookup
  44. Garcia-Gomez A, Guerrero-Barona E, Garcia-Pena I, Rodriguez-Jimenez M, Moreno-Manso JM. Equine-assisted therapeutic activities and their influence on the heart rate variability: A systematic review.. Complement. Ther. Clin. Pract. 39:101167.
    doi: 10.1016/j.ctcp.2020.101167pubmed: 32379693google scholar: lookup
  45. Gates MA, Holowka DW, Vasterling JJ, Keane TM, Marx BP, Rosen RC. Posttraumatic stress disorder in veterans and military personnel: epidemiology, screening, and case recognition.. Psychol. Serv. 9, 361–382.
    doi: 10.1037/a0027649pubmed: 23148803google scholar: lookup
  46. Gehrke EK, Baldwin A, Schiltz PM. Heart rate variability in horses engaged in equine-assisted activities. J. Equine Vet. Sci. 31, 78–84.
    doi: 10.1016/j.jevs.2010.12.007google scholar: lookup
  47. Geng D, Li X, Sun G. The effectiveness of exercise interventions in the improvement of sleep in older adult people: a meta-analysis. Front. Public Health 13:1529519.
    doi: 10.3389/fpubh.2025.1529519pmc: PMC11925204pubmed: 40115345google scholar: lookup
  48. Gilgen-Ammann R, Schweizer T, Wyss T. RR interval signal quality of a heart rate monitor and an ECG Holter at rest and during exercise. Eur. J. Appl. Physiol. 119, 1525–1532.
    doi: 10.1007/s00421-019-04142-5pubmed: 31004219google scholar: lookup
  49. Goldstein RB, Smith SM, Chou SP, Saha TD, Jung J, Zhang H. The epidemiology of DSM-5 posttraumatic stress disorder in the United States: results from the National Epidemiologic Survey on alcohol and related conditions-III. Soc. Psychiatry Psychiatr. Epidemiol. 51, 1137–1148.
    doi: 10.1007/s00127-016-1208-5pmc: PMC4980174pubmed: 27106853google scholar: lookup
  50. Goncalves R, Rodrigues H, Novaes F, Arbol J, Volchan E, Coutinho ES. Listening to the heart: A meta-analysis of cognitive behavior therapy impact on the heart rate of patients with anxiety disorders. J. Affect. Disord. 172, 231–240.
    doi: 10.1016/j.jad.2014.09.058pubmed: 25451422google scholar: lookup
  51. Grech P, Grech R. A comparison of narrative exposure therapy and non-trauma-focused treatment in post-traumatic stress disorder: A systematic review and Meta-analysis. Issues Ment. Health Nurs. 41, 91–101.
    doi: 10.1080/01612840.2019.1650853pubmed: 31661649google scholar: lookup
  52. Harvey AG, Jones C, Schmidt DA. Sleep and posttraumatic stress disorder: a review. Clin. Psychol. Rev. 23, 377–407.
    doi: 10.1016/s0272-7358(03)00032-1pubmed: 12729678google scholar: lookup
  53. Hauschildt M, Peters MJ, Moritz S, Jelinek L. Heart rate variability in response to affective scenes in posttraumatic stress disorder. Biol. Psychol. 88, 215–222.
    doi: 10.1016/j.biopsycho.2011.08.004pubmed: 21856373google scholar: lookup
  54. Hediger K, Meisser A, Zinsstag J. A one Health Research framework for animal-assisted interventions. Int. J. Environ. Res. Public Health 16:640.
    doi: 10.3390/ijerph16040640pmc: PMC6406415pubmed: 30795602google scholar: lookup
  55. Hinde K, White G, Armstrong N. Wearable devices suitable for monitoring twenty four hour heart rate variability in military populations. Sensors (Basel) 21:1061.
    doi: 10.3390/s21041061pmc: PMC7913967pubmed: 33557190google scholar: lookup
  56. Hoeboer CM, Karaban I, Karchoud JF, Olff M, van Zuiden M. Validation of the PCL-5 in Dutch trauma-exposed adults. BMC Psychol. 12:456.
    doi: 10.1186/s40359-024-01951-ypmc: PMC11351185pubmed: 39198929google scholar: lookup
  57. Hwang J, Fernandez AM, Lu AS. Application and validation of activity monitors' epoch lengths and placement sites for physical activity assessment in exergaming. J. Clin. Med. 7:268.
    doi: 10.3390/jcm7090268pmc: PMC6162850pubmed: 30208567google scholar: lookup
  58. Insana SP, Hall M, Buysse DJ, Germain A. Validation of the Pittsburgh sleep quality index addendum for posttraumatic stress disorder (PSQI-A) in U.S. male military veterans. J. Trauma. Stress. 26, 192–200.
    doi: 10.1002/jts.21793pmc: PMC3746481pubmed: 23512653google scholar: lookup
  59. Johnson RA, Albright DL, Marzolf JR, Bibbo JL, Yaglom HD, Crowder SM. Effects of therapeutic horseback riding on post-traumatic stress disorder in military veterans. Mil. Med. Res. 5:3.
    doi: 10.1186/s40779-018-0149-6pmc: PMC5774121pubmed: 29502529google scholar: lookup
  60. Kapteijn C, Reinders N, Hueting M, Van Huffelen RA, Vermetten E, Rodenburg B. Are equine assisted interactions (EAI) a dark horse bet? A systematic review on measuring the psychological and physiological effects of EAI on PTSD, anxiety and/or mood disorders.. Psychiatry Clin Psychopharmacol 35, S90–S112.
    doi: 10.5152/pcp.2025.24958pmc: PMC12410245pubmed: 40865011google scholar: lookup
  61. Kendall E, Maujean A, Pepping CA, Downes M, Lakhani A, Byrne J. A systematic review of the efficacy of equine-assisted interventions on psychological outcomes.. Eur. J. Psychother. Couns. 17, 57–79.
    doi: 10.1080/13642537.2014.996169google scholar: lookup
  62. Kim HG, Cheon EJ, Bai DS, Lee YH, Koo BH. Stress and heart rate variability: A Meta-analysis and review of the literature.. Psychiatry Investig. 15, 235–245.
    doi: 10.30773/pi.2017.08.17pmc: PMC5900369pubmed: 29486547google scholar: lookup
  63. Kinney AR, Eakman AM, Lassell R, Wood W. Equine-assisted interventions for veterans with service-related health conditions: a systematic mapping review.. Mil. Med. Res. 6:28.
    doi: 10.1186/s40779-019-0217-6pmc: PMC6714435pubmed: 31462305google scholar: lookup
  64. Kitchiner NJ, Lewis C, Roberts NP, Bisson JI. Active duty and ex-serving military personnel with post-traumatic stress disorder treated with psychological therapies: systematic review and meta-analysis.. Eur. J. Psychotraumatol. 10:1684226.
    doi: 10.1080/20008198.2019.1684226pmc: PMC6853217pubmed: 31762951google scholar: lookup
  65. Kristiansen. Comparison of two systems for long-term heart rate variability monitoring in free-living conditions - a pilot study.. Biomed. Eng. Online 10:27.
    doi: 10.1186/1475-925X-10-27pmc: PMC3080340pubmed: 21481282google scholar: lookup
  66. Lakens D. Calculating and reporting effect sizes to facilitate cumulative science: a practical primer for t-tests and ANOVAs.. Front. Psychol. 4:863.
    doi: 10.3389/fpsyg.2013.00863pmc: PMC3840331pubmed: 24324449google scholar: lookup
  67. Lanning BA, Wilson AL, Krenek N, Beaujean AA. Using therapeutic riding as an intervention for combat veterans: an international classification of functioning, disability, and health (ICF) approach.. Occup. Ther. Ment. Health 33, 259–278.
    doi: 10.1080/0164212X.2017.1283282google scholar: lookup
  68. Lanning BA, Wilson AL, Woelk R, Alexander Beaujean AA. Therapeutic horseback riding as a complementary intervention for military service members with PTSD.. Hum. Anim. Interact. Bull. 6, 58–82.
  69. Le QA, Doctor JN, Zoellner LA, Feeny NC. Minimal clinically important differences for the EQ-5D and QWB-SA in post-traumatic stress disorder (PTSD): results from a doubly randomized preference trial (DRPT).. Health Qual. Life Outcomes 11:59.
    doi: 10.1186/1477-7525-11-59pmc: PMC3635945pubmed: 23587015google scholar: lookup
  70. Levi O, Ben Yehuda A, Pine DS, Bar-Haim Y. A sobering look at treatment effectiveness of military-related posttraumatic stress disorder.. Clin. Psychol. Sci. 10, 690–699.
    doi: 10.1177/21677026211051314google scholar: lookup
  71. Li J, Sanchez-Garcia R. Equine-assisted interventions for veterans with posttraumatic stress disorder: a systematic review.. Front. Psych. 14:1277338.
    doi: 10.3389/fpsyt.2023.1277338pmc: PMC10654975pubmed: 38025432google scholar: lookup
  72. Malik M, Bigger JT, Camm AJ, Kleiger RE, Malliani A, Moss AJ. Heart rate variability: standards of measurement, physiological interpretation, and clinical use.. Eur. Heart J. 17, 354–381.
    doi: 10.1093/oxfordjournals.eurheartj.a014868pubmed: 8737210google scholar: lookup
  73. Malinowski K, Yee C, Tevlin JM, Birks EK, Durando MM, Pournajafi-Nazarloo H. The effects of equine assisted therapy on plasma cortisol and oxytocin concentrations and heart rate variability in horses and measures of symptoms of post-traumatic stress disorder in veterans.. J. Equine Vet. Sci. 64, 17–26.
    doi: 10.1016/j.jevs.2018.01.011pubmed: 30973147google scholar: lookup
  74. Marchand WR. Potential mechanisms of action and outcomes of equine-assisted Services for Veterans with a history of trauma: A narrative review of the literature.. Int. J. Environ. Res. Public Health 20:6377.
    doi: 10.3390/ijerph20146377pmc: PMC10379349pubmed: 37510609google scholar: lookup
  75. Marchand WR, Andersen SJ, Smith JE, Hoopes KH, Carlson JK. Equine-assisted activities and therapies for veterans with posttraumatic stress disorder: current state, challenges and future directions.. Chronic Stress 5:2470547021991556.
    doi: 10.1177/2470547021991556pmc: PMC7890715pubmed: 33644617google scholar: lookup
  76. Marx BP, Lee DJ, Norman SB, Bovin MJ, Sloan DM, Weathers FW. Reliable and clinically significant change in the clinician-administered PTSD scale for DSM-5 and PTSD checklist for DSM-5 among male veterans.. Psychol. Assess. 34, 197–203.
    doi: 10.1037/pas0001098pmc: PMC9022599pubmed: 34941354google scholar: lookup
  77. McDuffee LA, Montelpare WJ, LeBlanc C. Psychophysiological effects of equine-facilitated psychotherapy on veterans with PTSD and their horse partners.. J. Mil. Vet. Fam. Health 10, 135–147.
    doi: 10.3138/jmvfh-2023-0063google scholar: lookup
  78. Milligan T, Smolenski D, Lara-Ruiz J, Kelber MS. Loss of PTSD diagnosis in response to evidence-based treatments: A systematic review and Meta-analysis.. JAMA Psychiatry 82, 718–727.
    doi: 10.1001/jamapsychiatry.2025.0695pmc: PMC12096329pubmed: 40397424google scholar: lookup
  79. Mollayeva T, Thurairajah P, Burton K, Mollayeva S, Shapiro CM, Colantonio A. The Pittsburgh sleep quality index as a screening tool for sleep dysfunction in clinical and non-clinical samples: A systematic review and meta-analysis.. Sleep Med. Rev. 25, 52–73.
    doi: 10.1016/j.smrv.2015.01.009pubmed: 26163057google scholar: lookup
  80. Monroe M, Whitworth JD, Wharton T, Turner J. Effects of an equine-assisted therapy program for military veterans with self-reported PTSD.. Soc. Animals 29, 577–590.
    doi: 10.1163/15685306-12341572google scholar: lookup
  81. Mulick PS, Landes SJ, Kanter JW. Contextual behavior therapies in the treatment of PTSD: a review.. Int. J. Behav. Consult. Ther. 7, 23–31.
    doi: 10.1037/h0100923google scholar: lookup
  82. Murphy D, Ross J, Ashwick R, Armour C, Busuttil W. Exploring optimum cut-off scores to screen for probable posttraumatic stress disorder within a sample of UK treatment-seeking veterans.. Eur. J. Psychotraumatol. 8:1398001.
    doi: 10.1080/20008198.2017.1398001pmc: PMC5800736pubmed: 29435200google scholar: lookup
  83. Palomar-Ciria N, Bello HJ. Equine-assisted therapy in post-traumatic-stress disorder: A systematic review and Meta-analysis.. J. Equine Vet. Sci. 128:104871.
    doi: 10.1016/j.jevs.2023.104871pubmed: 37355148google scholar: lookup
  84. Park JE, Lee JY, Kang SH, Choi JH, Kim TY, So HS. Heart rate variability of chronic posttraumatic stress disorder in the Korean veterans.. Psychiatry Res. 255, 72–77.
    doi: 10.1016/j.psychres.2017.05.011pubmed: 28528244google scholar: lookup
  85. Peltola MA. Role of editing of R-R intervals in the analysis of heart rate variability.. Front. Physiol. 3:148.
    doi: 10.3389/fphys.2012.00148pmc: PMC3358711pubmed: 22654764google scholar: lookup
  86. Porten S, Friedmann F, Schoofs N, Barth C, Meyer K, Santangelo P. Subjective and objective sleep disturbances following trauma-focused treatment.. Eur. J. Psychotraumatol. 16:2542044.
    doi: 10.1080/20008066.2025.2542044pmc: PMC12392437pubmed: 40862670google scholar: lookup
  87. Powell C, Carson BP, Dowd KP, Donnelly AE. Simultaneous validation of five activity monitors for use in adult populations.. Scand. J. Med. Sci. Sports 27, 1881–1892.
    doi: 10.1111/sms.12813pubmed: 27905148google scholar: lookup
  88. Reijnen A, Rademaker AR, Vermetten E, Geuze E. Prevalence of mental health symptoms in Dutch military personnel returning from deployment to Afghanistan: a 2-year longitudinal analysis.. Eur. Psychiatry 30, 341–346.
    doi: 10.1016/j.eurpsy.2014.05.003pubmed: 25195152google scholar: lookup
  89. Rogers B, Giles D, Draper N, Mourot L, Gronwald T. Influence of artefact correction and recording device type on the practical application of a non-linear heart rate variability biomarker for aerobic threshold determination.. Sensors (Basel) 21:821.
    doi: 10.3390/s21030821pmc: PMC7865269pubmed: 33530473google scholar: lookup
  90. Romaniuk M, Evans J, Kidd C. Evaluation of an equine-assisted therapy program for veterans who identify as 'wounded, injured or ill' and their partners.. PLoS One 13:e0203943.
    doi: 10.1371/journal.pone.0203943pmc: PMC6160012pubmed: 30260975google scholar: lookup
  91. Rusch H L, Guardado P, Baxter T, Mysliwiec V, Gill J M. Improved sleep quality is associated with reductions in depression and PTSD arousal symptoms and increases in IGF-1 concentrations.. J. Clin. Sleep Med. 11, 615–623.
    doi: 10.5664/jcsm.4770pmc: PMC4442222pubmed: 25766717google scholar: lookup
  92. Sack M, Lempa W, Lamprecht F. Assessment of psychophysiological stress reactions during a traumatic reminder in patients treated with EMDR.. J. EMDR Pract. Res. 1, 15–23.
    doi: 10.1891/1933-3196.1.1.15google scholar: lookup
  93. Sareen J, Cox B J, Goodwin R D, Asmundson G J G. Co-occurrence of posttraumatic stress disorder with positive psychotic symptoms in a nationally representative sample.. J. Trauma. Stress. 18, 313–322.
    doi: 10.1002/jts.20040pubmed: 16281228google scholar: lookup
  94. Schnurr P P, Lunney C A, Bovin M J, Marx B P. Posttraumatic stress disorder and quality of life: extension of findings to veterans of the wars in Iraq and Afghanistan.. Clin. Psychol. Rev. 29, 727–735.
    doi: 10.1016/j.cpr.2009.08.006pubmed: 19744758google scholar: lookup
  95. Schoenfeld F B, Deviva J C, Manber R. Treatment of sleep disturbances in posttraumatic stress disorder: a review.. J. Rehabil. Res. Dev. 49, 729–752.
    doi: 10.1682/jrrd.2011.09.0164pubmed: 23015583google scholar: lookup
  96. Schottenbauer M A, Glass C R, Arnkoff D B, Tendick V, Gray S H. Nonresponse and dropout rates in outcome studies on PTSD: review and methodological considerations.. Psychiatry 71, 134–168.
    doi: 10.1521/psyc.2008.71.2.134pubmed: 18573035google scholar: lookup
  97. Shelef A, Brafman D, Rosing T, Weizman A, Stryjer R, Barak Y. Equine assisted therapy for patients with post traumatic stress disorder: A case series study.. Mil. Med. 184, 394–399.
    doi: 10.1093/milmed/usz036pubmed: 30839068google scholar: lookup
  98. Smith S M, Goldstein R B, Grant B F. The association between post-traumatic stress disorder and lifetime DSM-5 psychiatric disorders among veterans: data from the National Epidemiologic Survey on alcohol and related conditions-III (NESARC-III).. J. Psychiatr. Res. 82, 16–22.
    doi: 10.1016/j.jpsychires.2016.06.022pmc: PMC5026976pubmed: 27455424google scholar: lookup
  99. Starke J A, Stein D J. Management of treatment-resistant posttraumatic stress disorder.. Curr. Treat. Options Psychiatry 4, 387–403.
    doi: 10.1007/s40501-017-0130-0google scholar: lookup
  100. Steele E, Wood D S, E J U, Applegarth D M. TRR'S warrior camp: an intensive treatment program for combat trauma in active military and veterans of all eras.. Mil. Med. 183, 403–407.
    doi: 10.1093/milmed/usx153pubmed: 29635563google scholar: lookup
  101. Steenkamp M M, Litz B T, Hoge C W, Marmar C R. Psychotherapy for military-related PTSD: A review of randomized clinical trials.. JAMA 314, 489–500.
    doi: 10.1001/jama.2015.8370pubmed: 26241600google scholar: lookup
  102. Stern C, Chur-hansen A. An umbrella review of the evidence for equine-assisted interventions.. Aust. J. Psychol. 71, 361–374.
    doi: 10.1111/ajpy.12246google scholar: lookup
  103. Stout J W, Beidel D C, Alfano C A, Mesa F, Trachik B, Neer S M. Sleep disturbances among combat military veterans: a comparative study using subjective and objective sleep assessments.. Mil. Psychol. 29, 189–201.
    doi: 10.1037/mil0000161google scholar: lookup
  104. Tan G, Dao T K, Farmer L, Sutherland R J, Gevirtz R. Heart rate variability (HRV) and posttraumatic stress disorder (PTSD): a pilot study.. Appl. Psychophysiol. Biofeedback 36, 27–35.
    doi: 10.1007/s10484-010-9141-ypubmed: 20680439google scholar: lookup
  105. Tarvainen MP, Niskanen JP, Lipponen JA, Ranta-Aho PO, Karjalainen PA. Kubios HRV--heart rate variability analysis software. Comput. Methods Prog. Biomed. 113, 210–220.
    doi: 10.1016/j.cmpb.2013.07.024pubmed: 24054542google scholar: lookup
  106. Thomas JL, Wilk JE, Riviere LA, McGurk D, Castro CA, Hoge CW. Prevalence of mental health problems and functional impairment among active component and National Guard Soldiers 3 and 12 months following combat in Iraq. Arch. Gen. Psychiatry 67, 614–623.
    doi: 10.1001/archgenpsychiatry.2010.54pubmed: 20530011google scholar: lookup
  107. van der Wal SJ, Vermetten E, Elbert G. Long-term development of post-traumatic stress symptoms and associated risk factors in military service members deployed to Afghanistan: results from the PRISMO 10-year follow-up. Eur. Psychiatry 64:e10.
    doi: 10.1192/j.eurpsy.2020.113pmc: PMC8057418pubmed: 33342444google scholar: lookup
  108. Van Praag DLG, Fardzadeh HE, Covic A, Maas AIR, von Steinbuchel N. Preliminary validation of the Dutch version of the posttraumatic stress disorder checklist for DSM-5 (PCL-5) after traumatic brain injury in a civilian population. PLoS One 15:e0231857.
    doi: 10.1371/journal.pone.0231857pmc: PMC7170250pubmed: 32310970google scholar: lookup
  109. Versteegh MM, Vermeulen KM, Evers SMAA, de Wit GA, Prenger R, E AS. Dutch tariff for the five-level version of EQ-5D. Value Health 19, 343–352.
    doi: 10.1016/j.jval.2016.01.003pubmed: 27325326google scholar: lookup
  110. von Borell E, Langbein J, Despres G, Hansen S, Leterrier C, Marchant-Forde J. Heart rate variability as a measure of autonomic regulation of cardiac activity for assessing stress and welfare in farm animals -- a review. Physiol. Behav. 92, 293–316.
    doi: 10.1016/j.physbeh.2007.01.007pubmed: 17320122google scholar: lookup
  111. Watkins LE, Sprang KR, Rothbaum BO. Treating PTSD: A review of evidence-based psychotherapy interventions. Front. Behav. Neurosci. 12:258.
    doi: 10.3389/fnbeh.2018.00258pmc: PMC6224348pubmed: 30450043google scholar: lookup
  112. Wharton T, Whitworth J, Macauley E, Malone M. Pilot testing a manualized equine-facilitated cognitive processing therapy (EF-CPT) intervention for PTSD in veterans. Psychiatr. Rehabil. J. 42, 268–276.
    doi: 10.1037/prj0000359pubmed: 30907609google scholar: lookup
  113. Willmund G, Zimmermann P, Alliger-Horn C, Varn A, Fischer C, Parent I. Equine-assisted psychotherapy with traumatized couples-improvement of relationship quality and psychological symptoms. J. Marital. Fam. Ther. 47, 925–944.
    doi: 10.1111/jmft.12485pubmed: 33512042google scholar: lookup
  114. Wortmann JH, Jordan AH, Weathers FW, Resick PA, Dondanville KA, Hall-Clark B. Psychometric analysis of the PTSD Checklist-5 (PCL-5) among treatment-seeking military service members. Psychol. Assess. 28, 1392–1403.
    doi: 10.1037/pas0000260pubmed: 26751087google scholar: lookup
  115. Yang M, Mady N, Linnaranta O. Utility of psychophysiological metrics in guiding treatment of trauma symptoms: a systematic review. J. Behav. Cognitive Therapy 31, 249–266.
    doi: 10.1016/j.jbct.2021.01.004google scholar: lookup
  116. Zhu X, Suarez-Jimenez B, Zilcha-Mano S, Lazarov A, Arnon S, Lowell AL. Neural changes following equine-assisted therapy for posttraumatic stress disorder: A longitudinal multimodal imaging study. Hum. Brain Mapp. 42, 1930–1939.
    doi: 10.1002/hbm.25360pmc: PMC7978114pubmed: 33547694google scholar: lookup

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