FREE SHIPPING over $40
OVER 10000 FIVE-STAR REVIEWS
5% OFF ALL SUBSCRIPTIONS
100% HAPPINESS GUARANTEE
Analyze Diet
0
Psychiatry and clinical psychopharmacology2025; 35(Suppl 1); S90-S112; doi: 10.5152/pcp.2025.24958

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.

Abstract: Background: Conventional forms of trauma-focused psychological interventions seem to be less effective in military veterans with post-traumatic stress disorder (PTSD). Equine Assisted Interventions (EAI) have become increasingly popular as an additional treatment, resulting in increasing research on the effects of EAI. However, no systematic review on the effects of EAI has focused on PTSD, anxiety and/or mood disorders and whether the effects are reflected in psychological and physiological measures. This systematic review investigated the treatment effects, study design, population, intervention, and psychological and physiological measurements in EAI research. Methods: The search strategy yielded 1028 original articles from 3 electronic databases: PubMed, Scopus, and CAB Abstracts. These articles were screened by 2 individual blinded researchers with Rayyan according to Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines and rendered 31 eligible studies. Results: Although all quantitative studies reported 1 or more positive treatment effects on symptoms of PTSD, anxiety and/or mood disorders, well-designed studies were sparse. This review demonstrated a lack of methodological information and few randomized controlled studies, in addition to a large heterogeneity in population characteristics, interventions, terminology, and questionnaires. Conclusion: Future studies should address these methodological considerations in order to advance the understanding of EAI and optimize their efficacy in treating PTSD, anxiety and/or mood disorders.
Get Full Text
Publication Date: 2025-08-27 PubMed ID: 40865011PubMed Central: PMC12410245DOI: 10.5152/pcp.2025.24958Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
LinkedInCopy
  • Journal Article

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 research systematically reviewed existing studies on the use of Equine Assisted Interventions (EAI) for treating PTSD, anxiety, and mood disorders, focusing on both psychological and physiological outcomes.
  • While many studies reported positive effects, the review highlights significant methodological limitations and variability, suggesting the need for more rigorous research to confirm and optimize the benefits of EAI.

Background

  • Conventional psychological treatments targeting trauma, especially for military veterans with PTSD, often show limited effectiveness.
  • Equine Assisted Interventions (EAI), therapy involving interactions with horses, are gaining popularity as an alternative or complementary approach for mental health treatment.
  • Prior to this study, no comprehensive systematic review specifically examined EAI’s effects on PTSD, anxiety, and mood disorders by assessing both psychological symptoms and physiological measures.

Research Objectives

  • To systematically review the treatment effects of EAI on PTSD, anxiety, and mood disorders.
  • To analyze the study designs, populations involved, types of EAI interventions used, and the psychological and physiological outcome measures applied.
  • To identify gaps and inconsistencies in the existing research literature.

Methods

  • Database Search: Three electronic databases were searched—PubMed, Scopus, and CAB Abstracts—yielding 1028 original articles.
  • Screening: Two independent, blinded researchers screened the articles using the Rayyan software following PRISMA guidelines.
  • Inclusion: After screening, 31 studies met eligibility criteria to be included in the systematic review.

Key Findings

  • Positive Effects: Every quantitative study included reported at least one positive treatment effect of EAI on symptoms of PTSD, anxiety, or mood disorders.
  • Methodological Concerns: Despite positive findings, there was a scarcity of well-designed studies, especially randomized controlled trials (RCTs), considered the gold standard for clinical research.
  • Heterogeneity: There was substantial variability in the characteristics of study populations (e.g., different demographics and clinical profiles), types of EAI interventions, terminology used across studies, and questionnaires/measurement tools.
  • Physiological Measures: Fewer studies incorporated physiological outcomes alongside psychological assessments, limiting understanding of the full scope of EAI effects.
  • Reporting Gaps: Many studies lacked detailed methodological information which hinders replication and thorough evaluation of study quality.

Conclusions and Recommendations

  • Although EAI shows promise as a complementary therapy for PTSD, anxiety, and mood disorders, the current evidence base is limited by methodological weaknesses and inconsistency.
  • Future research should prioritize:
    • Conducting more randomized controlled trials to provide high-quality evidence.
    • Standardizing intervention protocols and terminology to reduce heterogeneity.
    • Incorporating both psychological and physiological outcome measures to fully capture treatment effects.
    • Detailed reporting of study methodologies to improve reproducibility and allow for meta-analytic synthesis.
  • Addressing these issues will help clarify the therapeutic potential of EAI and optimize its use in clinical settings, especially for populations where conventional treatments are less effective.

Cite This Article

APA
Kapteijn C, Reinders N, Hueting M, Van Huffelen RA, Vermetten E, Rodenburg B, Endenburg N. (2025). 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(Suppl 1), S90-S112. https://doi.org/10.5152/pcp.2025.24958

Publication

Psychiatry and clinical psychopharmacology
ISSN: 2475-0581
NlmUniqueID: 101712793
Country: England
Language: English
Volume: 35
Issue: Suppl 1
Pages: S90-S112

Researcher Affiliations

Kapteijn, Chantal
  • Animals in Science & Society, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
Reinders, Nadieh
  • Animals in Science & Society, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
Hueting, Martine
  • Military Mental Health Care Ministry of Defense, Utrecht, The Netherlands.
Van Huffelen, Rogier Alexander
  • Mentrum Psychiatric Hospital, Amsterdam, The Netherlands.
Vermetten, Eric
  • Department of Psychiatry, Leiden University Medical Centre, Leiden, The Netherlands.
Rodenburg, Bas
  • Animals in Science & Society, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
  • Adaptation Physiology Group, Wageningen University and Research, Wageningen, The Netherlands.
Endenburg, Nienke
  • Animals in Science & Society, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.

Conflict of Interest Statement

Eric Vermetten is an Associate Editor at Psychiatry and Clinical Psychopharmacology, however, his involvement in the peer-review process was solely as an author. The other authors have no conflict of interest to declare.

References

This article includes 62 references
  1. Coventry PA, Meader N, Melton H. 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.
    doi: 10.1371/journal.pmed.1003262pmc: PMC7446790pubmed: 32813696google scholar: lookup
  2. Gehrke EK, Baldwin A, Schiltz PM. Heart rate variability in horses engaged in equine-assisted activities. J Equine Vet Sci 2011;31(2):78 84.
    doi: 10.1016/j.jevs.2010.12.007google scholar: lookup
  3. Boss L, Branson S, Hagan H, Krause-Parello C. A systematic review of equine-assisted interventions in military veterans diagnosed with PTSD. J Vet Stud 2019;5(1).
    doi: 10.21061/jvs.v5i1.134google scholar: lookup
  4. Malinowski K, Yee C, Tevlin JM. 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 2018;64:17 26.
    doi: 10.1016/j.jevs.2018.01.011pubmed: 30973147google scholar: lookup
  5. 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 2018;13(9):e0203943.
    doi: 10.1371/journal.pone.0203943pmc: PMC6160012pubmed: 30260975google scholar: lookup
  6. Burton LE, Qeadan F, Burge MR. Efficacy of equine-assisted psychotherapy in veterans with posttraumatic stress disorder. J Integr Med 2019;17(1):14 19.
    doi: 10.1016/j.joim.2018.11.001pubmed: 30497951google scholar: lookup
  7. 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 (Thousand Oaks) 2021;5:2470547021991556.
    doi: 10.1177/2470547021991556pmc: PMC7890715pubmed: 33644617google scholar: lookup
  8. Hallberg L. The Clinical Practice of Equine-Assisted Therapy: Including Horses in Human Healthcare. Abingdon, UK: Routledge; 2017.
    doi: 10.4324/9781315545905google scholar: lookup
  9. Stern C, Chur‐hansen A. An umbrella review of the evidence for equine‐assisted interventions. Aust J Psychol 2019;71(4):361 374.
    doi: 10.1111/ajpy.12246google scholar: lookup
  10. Anestis MD, Anestis JC, Zawilinski LL, Hopkins TA, Lilienfeld SO. Equine-related treatments for mental disorders lack empirical support: a systematic review of empirical investigations. J Clin Psychol 2014;70(12):1115 1132.
    doi: 10.1002/jclp.22113pubmed: 24953870google scholar: lookup
  11. Lee PT, Dakin E, McLure M. Narrative synthesis of equine-assisted psychotherapy literature: current knowledge and future research directions. Health Soc Care Community 2016;24(3):225 246.
    doi: 10.1111/hsc.12201pubmed: 25727575google scholar: lookup
  12. 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 2019;6(1):28.
    doi: 10.1186/s40779-019-0217-6pmc: PMC6714435pubmed: 31462305google scholar: lookup
  13. Rigby BR, Davis RW, Bittner MD, Harwell RW, Johnson GA, Nichols DL. Changes in motor skill proficiency after equine-assisted activities and brain-building tasks in youth with neurodevelopmental disorders. Front Vet Sci 2020;7(22).
    doi: 10.3389/fvets.2020.00022pmc: PMC7004954pubmed: 32083104google scholar: lookup
  14. Tseng SH, Chen HC, Tam KW. Systematic review and meta-analysis of the effect of equine assisted activities and therapies on gross motor outcome in children with cerebral palsy. Disabil Rehabil 2013;35(2):89 99.
    doi: 10.3109/09638288.2012.687033pubmed: 22630812google scholar: lookup
  15. Beetz A, Uvnäs-Moberg K, Julius H, Kotrschal K. Psychosocial and psychophysiological effects of human-animal interactions: the possible role of oxytocin. Front Psychol 2012;3:234.
    doi: 10.3389/fpsyg.2012.00234pmc: PMC3408111pubmed: 22866043google scholar: lookup
  16. Ishak WW, Kahloon M, Fakhry H. Oxytocin role in enhancing well-being: a literature review. J Affect Disord 2011;130(1-2):1 9.
    doi: 10.1016/j.jad.2010.06.001pubmed: 20584551google scholar: lookup
  17. Uvnäs-Moberg K. Oxytocin may mediate the benefits of positive social interaction and emotions. Psychoneuroendocrinology 1998;23(8):819 835.
    doi: 10.1016/s0306-4530(98)00056-0pubmed: 9924739google scholar: lookup
  18. Handlin L, Hydbring-Sandberg E, Nilsson A, Ejdebäck M, Jansson A, Uvnäs-Moberg K. Short-term interaction between dogs and their owners: effects on oxytocin, cortisol, insulin and heart rate—an exploratory study. Anthrozoös 2011;24(3):301 315.
    doi: 10.2752/175303711X13045914865385google scholar: lookup
  19. Odendaal JS, Meintjes RA. Neurophysiological correlates of affiliative behaviour between humans and dogs. Vet J 2003;165(3):296 301.
    doi: 10.1016/s1090-0233(02)00237-xpubmed: 12672376google scholar: lookup
  20. Collado-Mateo D, Lavín-Pérez AM, Fuentes García JP, García-Gordillo MÁ, Villafaina S. Effects of equine-assisted therapies or horse-riding simulators on chronic pain: a systematic review and meta-analysis. Medicina (Kaunas) 2020;56(9):444.
    doi: 10.3390/medicina56090444pmc: PMC7557603pubmed: 32878327google scholar: lookup
  21. Holmes MA. Evaluation of the evidence. Vet Clin North Am Small Anim Pract 2007;37(3):447 462.
    doi: 10.1016/j.cvsm.2007.01.004pubmed: 17466749google scholar: lookup
  22. Alfonso SV, Alfonso LA, Llabre MM, Fernandez MI. Project Stride: an Equine-Assisted Intervention to Reduce Symptoms of Social Anxiety in Young Women. Explore (NY) 2015;11(6):461 467.
    doi: 10.1016/j.explore.2015.08.003pubmed: 26386749google scholar: lookup
  23. Johnson RA, Albright DL, Marzolf JR. Effects of therapeutic horseback riding on post-traumatic stress disorder in military veterans. Mil Med Res 2018;5(1):3.
    doi: 10.1186/s40779-018-0149-6pmc: PMC5774121pubmed: 29502529google scholar: lookup
  24. Willmund G, Zimmermann P, Alliger-Horn C. Equine-assisted psychotherapy with traumatized couples-Improvement of relationship quality and psychological symptoms. J Marital Fam Ther 2021;47(4):925 944.
    doi: 10.1111/jmft.12485pubmed: 33512042google scholar: lookup
  25. Lanning BA, Wilson AL, Woelk R, Beaujean AA. Therapeutic horseback riding as a complementary intervention for military service members with PTSD. Human-animal interaction bulletin 2018;6(2):58 82.
    doi: 10.1079/hai.2018.0013google scholar: lookup
  26. Mueller MK, McCullough L. Effects of equine-facilitated psychotherapy on post-traumatic stress symptoms in youth. J Child Fam Stud 2017;26(4):1164 1172.
    doi: 10.1007/s10826-016-0648-6google scholar: lookup
  27. Arnon S, Fisher PW, Pickover A. Equine-assisted therapy for veterans with PTSD: manual development and preliminary findings. Mil Med 2020;185(5-6):e557 e564.
    doi: 10.1093/milmed/usz444pmc: PMC7282489pubmed: 32034416google scholar: lookup
  28. Chakales PA, Locklear J, Wharton T. Medicine and horsemanship: the effects of equine-assisted activities and therapies on stress and depression in medical students. Cureus 2020;12(2):e6896.
    doi: 10.7759/cureus.6896pmc: PMC7059872pubmed: 32195063google scholar: lookup
  29. Earles JL, Vernon LL, Yetz JP. Equine-assisted therapy for anxiety and posttraumatic stress symptoms. J Trauma Stress 2015;28(2):149 152.
    doi: 10.1002/jts.21990pubmed: 25782709google scholar: lookup
  30. Fisher PW, Lazarov A, Lowell A. Equine-assisted therapy for posttraumatic stress disorder among military veterans: an open trial. J Clin Psychiatry 2021;82(5):21m14005.
    doi: 10.4088/JCP.21m14005pubmed: 34464523google scholar: lookup
  31. Monroe M, Whitworth JD, Wharton T, Turner J. Effects of an equine-assisted therapy program for military veterans with self-reported PTSD. Soc Animals 2019;29(5-6):577 590.
    doi: 10.1163/15685306-12341572google scholar: lookup
  32. Steele E, Wood DS, J Usadi E, Applegarth DM. TRR’s warrior camp: an intensive treatment program for combat trauma in active military and veterans of all eras. Mil Med 2018;183(Suppl 1):403 407.
    doi: 10.1093/milmed/usx153pubmed: 29635563google scholar: lookup
  33. Zhu X, Suarez-Jimenez B, Zilcha-Mano S. Neural changes following equine-assisted therapy for posttraumatic stress disorder: a longitudinal multimodal imaging study. Hum Brain Mapp 2021;42(6):1930 1939.
    doi: 10.1002/hbm.25360pmc: PMC7978114pubmed: 33547694google scholar: lookup
  34. 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 2017;33(3):259 278.
    doi: 10.1080/0164212X.2017.1283282google scholar: lookup
  35. McCullough L, Risley-Curtiss C, Rorke J. Equine facilitated psychotherapy: a pilot study of effect on posttraumatic stress symptoms in maltreated youth. J Infant Child Adolesc Psychother 2015;14(2):158 173.
    doi: 10.1080/15289168.2015.1021658google scholar: lookup
  36. Acri M, Morrissey M, Peth-Pierce R. An equine-assisted therapy for youth with mild to moderate anxiety: manual development and fidelity. J Child Fam Stud 2021;30(10):2461 2467.
    doi: 10.1007/s10826-021-02011-4google scholar: lookup
  37. Schroeder K, Stroud D. Equine-facilitated group work for women survivors of interpersonal violence. J Spec Group Work 2015;40(4):365 386.
    doi: 10.1080/01933922.2015.1082684google scholar: lookup
  38. 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 2019;42(3):268 276.
    doi: 10.1037/prj0000359pubmed: 30907609google scholar: lookup
  39. Ferruolo DM. Psychosocial equine program for veterans. Soc Work 2016;61(1):53 60.
    doi: 10.1093/sw/swv054pubmed: 26897999google scholar: lookup
  40. Meyer L, Sartori A. Attachment theory and equine-facilitated psychotherapy for Vietnam veterans. Soc Animals 2019;27(3):288 306.
    doi: 10.1163/15685306-12341510google scholar: lookup
  41. Naste TM, Price M, Karol J. Equine facilitated therapy for complex trauma (EFT-CT). J Child Adolesc Trauma 2018;11(3):289 303.
    doi: 10.1007/s40653-017-0187-3pmc: PMC6132374pubmed: 30220956google scholar: lookup
  42. Nevins R, Finch S, Hickling EJ, Barnett SD. The Saratoga WarHorse project: a case study of the treatment of psychological distress in a veteran of Operation Iraqi Freedom. Adv Mind Body Med 2013;27(4):22 25.
    pubmed: 24067322
  43. Yorke J, Adams C, Coady N. Therapeutic value of equine - human bonding in recovery from trauma. Anthrozoos 2008;21(1):17 30.
    doi: 10.2752/089279308X274038google scholar: lookup
  44. Rosing T, Malka M, Brafman D, Fisher PW. A qualitative study of equine-assisted therapy for Israeli military and police veterans with PTSD-impact on self-regulation, bonding and hope. Health Soc Care Community 2022;30(6):e5074 e5082.
    doi: 10.1111/hsc.13922pubmed: 35852225google scholar: lookup
  45. 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 2019;184(9-10):394 399.
    doi: 10.1093/milmed/usz036pubmed: 30839068google scholar: lookup
  46. Johnson RA, Albright DL, Marzolf JR. Experiences of military veterans in a therapeutic horseback riding program. Clin Nurs Res 2021;30(7):923 933.
    doi: 10.1177/10547738211003580pubmed: 33855883google scholar: lookup
  47. Craig EA. Equine-assisted psychotherapy among adolescents with ACEs: cultivating Altercentrism, expressiveness, communication composure, and interaction management. Child Adolesc Soc Work J 2020;37(6):643 656.
    doi: 10.1007/s10560-020-00694-0google scholar: lookup
  48. Craig EA, Nieforth L, Rosenfeld C. Communicating resilience among adolescents with adverse childhood experiences (ACEs) through equine assisted psychotherapy (EAP). West J Commun 2020;84(4):400 418.
    doi: 10.1080/10570314.2020.1754451google scholar: lookup
  49. Sylvia L, West E, Blackburn AM. Acceptability of an adjunct equine-assisted activities and therapies program for veterans with posttraumatic stress disorder and/or traumatic brain injury. J Integr Med 2020;18(2):169 173.
    pubmed: 31996299
  50. Campbell HM, Raisch DW, Sather MR, Warren SR, Segal AR. A comparison of veteran and nonveteran motivations and reasons for participating in clinical trials. Mil Med 2007;172(1):27 30.
    doi: 10.7205/milmed.172.1.27pubmed: 17274261google scholar: lookup
  51. Varker T, Jones KA, Arjmand H-A. Dropout from guideline-recommended psychological treatments for posttraumatic stress disorder: a systematic review and meta-analysis. J Affect Disord Rep 2021;4.
    doi: 10.1016/j.jadr.2021.100093google scholar: lookup
  52. Edwards-Stewart A, Smolenski DJ, Bush NE. Posttraumatic stress disorder treatment dropout among military and veteran populations: a systematic review and meta-analysis. J Trauma Stress 2021;34(4):808 818.
    doi: 10.1002/jts.22653pubmed: 33524199google scholar: lookup
  53. Imel ZE, Laska K, Jakupcak M, Simpson TL. Meta-analysis of dropout in treatments for posttraumatic stress disorder. J Consult Clin Psychol 2013;81(3):394 404.
    doi: 10.1037/a0031474pmc: PMC3893277pubmed: 23339535google scholar: lookup
  54. Mulick PS, Landes SJ, Kanter JW. Contextual behavior therapies in the treatment of PTSD: a review. Int J Behav Consult Ther 2011;7(1):23 31.
  55. Vujanovic AA, Youngwirth NE, Johnson KA, Zvolensky MJ. Mindfulness-based acceptance and posttraumatic stress symptoms among trauma-exposed adults without axis I psychopathology. J Anxiety Disord 2009;23(2):297 303.
    doi: 10.1016/j.janxdis.2008.08.005pmc: PMC2655122pubmed: 18834701google scholar: lookup
  56. Thompson BL, Waltz J. Mindfulness and experiential avoidance as predictors of posttraumatic stress disorder avoidance symptom severity. J Anxiety Disord 2010;24(4):409 415.
    doi: 10.1016/j.janxdis.2010.02.005pubmed: 20304602google scholar: lookup
  57. Bernstein A, Tanay G, Vujanovic AA. Concurrent relations between mindful attention and awareness and psychopathology among trauma-exposed adults. J Cogn Psychother 2011;25(2):99 113.
    doi: 10.1891/0889-8391.25.2.99google scholar: lookup
  58. Vujanovic AA, Niles BL, Pietrefesa A, Schmertz SK, Potter CM. Mindfulness in the treatment of posttraumatic stress disorder among military veterans. Prof Psychol Res Pract 2011;42(1):24 31.
  59. Yang M, Mady N, Linnaranta O. Utility of psychophysiological metrics in guiding treatment of trauma symptoms: a systematic review. J Behav Cogn Ther 2021;31(3):249 266.
  60. Hyde J, Ryan KM, Waters AM. Psychophysiological Markers of Fear and Anxiety. Curr Psychiatry Rep 2019;21(7):56.
    doi: 10.1007/s11920-019-1036-xpubmed: 31161250google scholar: lookup
  61. Bylsma LM. Emotion context insensitivity in depression: toward an integrated and contextualized approach. Psychophysiology 2021;58(2):e13715.
    doi: 10.1111/psyp.13715pmc: PMC8097691pubmed: 33274773google scholar: lookup
  62. Hama H, Yogo M, Matsuyama Y. Effects of stroking horses on both humans’ and horses’ heart rate responses1. Jpn Psychol Res 1996;38(2):66 73.

Citations

This article has been cited 0 times.
Subscribe to our newsletter
Join 100,127 horse owners like you who receive our email updates on horse health and nutrition.