The VA Office of Patient Centered Care and Cultural Transformation's Whole Health initiative promotes the use of complementary and integrative health (CIH) approaches with traditional medical care to help Veterans achieve meaningful life goals and improved functioning. Equine-facilitated therapy (EFT), an animal-assisted form of CIH, is increasingly available to Veterans within the VA. Horses have extreme sensitivity to the emotional states, behaviors, and intentions of their herds and other animals, including humans, and mirror body language and respond to subtle nonverbal cues. As such, horses have the capacity to provide immediate feedback about a people's emotional and behavioral states. This capacity affords people opportunities to become more emotionally self-aware and, with guidance from EFT facilitators, learn how to regulate emotions and become calmer and more patient, attentive, and confident to gain the horses' cooperation. Participants in EFT are encouraged to apply what they have learned from their equine experiences to their relationships with people. Since high quality social functioning depends on effective regulation of one's emotions, EFT offers a novel way in which to improve the social functioning of Veterans with mental health concerns. VAs are increasingly embracing EFT as a CIH. However, carefully conducted, scientifically valid research about EFT has not been conducted. Existing peer-reviewed research about EFT for mental health is very limited, of poor methodological quality, and not focused on adults. None of it targets social functioning as a main outcome. This small randomized controlled pilot study proposes to examine an innovative EFT called The Equus Effect (TEE) as a complement to Veterans' existing VA mental health services to improve social functioning. TEE aims to improve Veterans' social functioning by developing their emotion regulation and interpersonal skills through therapeutic interactions with horses. This study will evaluate 1) the feasibility of study procedures, assessments, and outcomes, 2) the fidelity of experimental and control interventions, and 3) the acceptability of the interventions to Veterans and their mental health clinicians using mixed quantitative-qualitative methods. The study has the potential to lend initial credibility to the therapeutic claims of this increasingly popular CIH.

**Please note that as a consequence of the COVID-19 pandemic, and after consultation with the appropriate research oversight, regulatory and monitoring entities, screening and enrollment was placed on temporary administrative hold from 04/30/2020 - 3/31/2022. Experimental and comparator conditions had to occur in person, in groups, and with van transportation to and from the intervention site. The study resumed preparations for the pilot trial 4/1/2022 and began participant screening and recruitment 6/15/2022.**

The VA Office of Patient Centered Care and Cultural Transformation launched the Whole Health initiative to transform the Veterans Health Administration into a healthcare system in which providers and Veterans develop holistic, personalized, proactive, patient-driven healthcare plans that center on realizing meaningful life goals and improved functioning. Whole Health promotes the use of complementary and integrative health (CIH) approaches with traditional medical care to achieve these aims - consistent with psychosocial rehabilitation's emphasis on recovery-oriented, community-based functional outcomes. Equine-facilitated therapy (EFT), an animal-assisted form of CIH, is increasingly available to Veterans within the VA. Horses are prey animals with extreme sensitivity to the emotional states, behaviors, and intentions of their herds and other animals, including humans, and mirror body language and respond to subtle nonverbal cues. As such, horses have the capacity to provide immediate feedback about a person's emotional and behavioral states (e.g., pinning ears back when someone is angry or relaxing them forward when a person is calm). As a person interacts with horses, this capacity affords him or her an opportunity to become more emotionally self-aware and, with guidance from EFT facilitators, learn how to regulate emotions and become calmer and more patient, attentive, and confident to gain the horses' cooperation. With EFT, emotion regulation is the key mechanism for social interaction with horses, and participants in EFT are encouraged to apply what they have learned from their equine experiences to their relationships with people. Since high quality social functioning depends on effective regulation of one's emotions, EFT offers a novel way in which to improve the social functioning of Veterans with mental health concerns. In fact, in the VA, EFT has been used to address a variety of diagnostic issues commonly experience by Veterans, including PTSD, depression, anxiety, substance use and eating disorders. However, peer-reviewed published quantitative and qualitative research on EFT as a CIH for mental health is very limited, of poor methodological quality, and focused on school-age children and adolescents, not adults. None of it targets social functioning as a main outcome. Given VAs increasing embrace of EFT as a CIH, carefully conducted research that aims to systematically develop and study EFT for Veterans is sorely needed to ensure that EFT is feasible to study, acceptable to Veterans and clinicians, and clinically promising.

The investigators propose to pilot test an innovative EFT called The Equus Effect (TEE) as a complement to Veterans' existing VA mental health services to improve social functioning. TEE aims to improve Veterans' social functioning by developing their emotion regulation and interpersonal skills through therapeutic interactions with horses. In line with recommendations for pilot investigations, the investigators will conduct a randomized pilot study to 1) evaluate the feasibility of study procedures, assessments, and outcomes, 2) demonstrate experimental and control interventions can be delivered with fidelity, and 3) examine the acceptability of the interventions. To accomplish these goals, the investigators will enroll a transdiagnostic cohort of 40 Veterans involved in VA mental health services with social dysfunction and emotion dysregulation. Participants will be randomized to receive either 1) TEE or 2) attention control (AC), both group interventions. Each week, the 4-session TEE will include 1) mindfulness activities, 2) emotion regulation and interpersonal skills education, 3) experiential activities with horses incorporating opportunities to develop emotion regulation and interpersonal skills, and 4) between-session application of lessons learned from the equine activities. AC will have similar elements without equine features. Intervention outcomes will be measured at 4- and 16-weeks post randomization. Specifically, using mixed quantitative-qualitative methods, the investigators aim to:

Aim 1: Determine the feasibility of recruitment, randomization, retention, assessment procedures, and implementation of TEE and AC. Hypothesis: Rates of recruitment will be at least 8 participants per month, and Veterans randomized to TEE will attend intervention sessions, remain in the study, and experience clinically significant changes in social functioning and emotion dysregulation at rates equal to or superior to AC.

Aim 2: Demonstrate TEE and AC can be delivered with fidelity. Hypothesis: Facilitators will deliver each intervention consistently and as intended across sessions.

Aim 3: Establish acceptability of TEE and AC by assessing intervention credibility and satisfaction and the usefulness of TEE as a complementary mental health intervention using mixed quantitative-qualitative methods. Hypothesis: Veterans will find TEE and AC credible and satisfying and Veterans and their mental health clinicians will qualitatively report the therapeutic benefits of TEE as a CIH for mental health treatment.

Inclusion Criteria:

• seeing a VA Connecticut mental health clinician at least 3 times in the past 3 months with intent to remain in treatment during study enrollment;
• age 18 and over;
• social dysfunction (score > 2.5 on the Social Adjustment Scale-Self Report (SAS-SR) and > 1.5 on Inventory of Interpersonal Problems-32 (IIP-32);
• emotion dysregulation (score > 95 on the Difficulties in Emotion Regulation Scale (DERS);
• sufficient mobility to participate in study procedures, as determined by PI;
• consent to all study procedures, including audio recording of TEE and AC sessions.

Exclusion Criteria:

• psychotic disorder per self-report and verified in medical record or as determined by the Mini-International Neuropsychiatric Interview (MINI);
• acute suicidality;
• inability to read English or communicate in spoken English;
• anticipated unavailability to the study during the next 20 weeks;
• participation in any equine-facilitated therapy in the past 24 weeks;
• unavailability of a landline or cellular telephone.

This is a small pilot study to determine feasibility and acceptability of testing equine-facilitated therapy within a randomized clinical trial design. It will not establish efficacy of the intervention, per se. Nonetheless, the PI will review and consider requests for sharing data with other investigators, after the PI has fully analyzed and published data generated from this trial.

After one year of study completion

Interested parties may email the PI to request data sharing.

Adverse event information was collected from June 2022 through July 2023, the period of time when all screening, baseline and 4-week and 16-week post-randomization assessments occurred.

clinicaltrials.gov definitions were used.

The pilot study had a small sample size not powered to detect statistically significant differences in clinical outcomes. It also examined the feasibility and acceptability of one specific equine-facilitated therapy; other equine-facilitated therapy programs may differ from the one we studied. Finally, follow-up was 3-months post-intervention. The feasibility of studying longer follow-up periods was not examined.

The research assistant who will collect study assessments will not know the randomization of participants to conditions. Randomization will be conducted by the study coordinator.