An interventional study of OTEE HORS and OT Clinic in Autism Spectrum Disorder, sponsored by Colorado State University. Completed at 1 site in United States. Open to participants aged 6 Years to 11 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-02.
Sponsored by Colorado State University · Not applicable, Interventional, and Treatment
The goal of this clinical trial is to learn about occupational therapy integrating horses for autistic youth. The main questions it aims to answer are:
Participants will receive 10 weeks of occupational therapy, and will be asked to provide saliva samples each week.
Researchers will compare occupational therapy integrating horses to occupational therapy in a clinic to see if integrating horses affects self-regulation.
The goal of this project is to quantify the unique benefits of integrating horses in occupational therapy compared to occupational therapy in a clinic (i.e., OTEE HORS vs. OT Clinic) for improving self-regulation in youth with ASD.
To address both aims we will randomize 64 youth with ASD ages 6-11 years old to OTEE HORS or OT clinic.
Specific Aim 1: Examine the preliminary efficacy of OTEE HORS compared to OT Clinic on self-regulation. Hypotheses: The OTEE HORS group will demonstrate significantly larger improvements than the OT Clinic group in five domains of self-regulation (hyperactivity [primary], irritability, emotional reactivity, dysphoria, and individual goal attainment).
Specific Aim 2: Identify potential physiological mechanisms that explain how integration of horses in occupational therapy impacts self-regulation in youth with ASD. Hypotheses 2A \& B: The OTEE HORS group will demonstrate significantly larger decreases in salivary cortisol after each 60-minute therapy session and after the 10-week treatment course in comparison to the OT Clinic group. Hypotheses 2C \& 2D: The OTEE HORS group will demonstrate significantly greater increases in salivary alpha-amylase after each 60-minute therapy session, and significantly greater decreases in salivary alpha-amylase over time as measured after the 10-week treatment course in comparison to the OT Clinic group. Exploratory Hypothesis 2E: Changes in physiological measures will significantly correlate with changes in Aim 1 behavioral measures.
1,724 studies on the registry are indexed under Autism Spectrum Disorder; 500 are open to participants now.
This study's enrollment of 72 is above the median of 52 across 1,368 interventional studies indexed under Autism Spectrum Disorder.
Browse Autism Spectrum Disorder studies →Colorado State University is the lead sponsor of 117 studies on the registry; 19 are open to participants now.
Of its 5 completed or terminated interventional studies of FDA-regulated products, 3 (60%) have results posted.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
10 weeks of occupational therapy focused on self-regulation skills, provided while participants are riding horses
Behavioral: OTEE HORS
10 weeks of occupational therapy focused on self-regulation skills, provided in a traditional clinic environment
Behavioral: OT Clinic
10 weeks of occupational therapy focused on teaching and practicing self-regulation skills, provided while participants are riding horses
10 weeks of occupational therapy focused on teaching and practicing self-regulation skills, provided in a traditional clinic
Change in Hyperactivity
The Hyperactivity subscale of the Aberrant Behavior Checklist, Second Edition (ABC-2) measures parent/caregiver-reported hyperactive and impulsive behaviors, including excessive activity, impulsivity, and difficulty remaining still or attending. The subscale consists of 16 items, with total scores ranging from 0-48. Higher scores indicate greater hyperactivity and more severe behavioral difficulties, while lower scores indicate less hyperactivity and better behavioral functioning. Item scores are summed to produce the subscale score.
Time frame: Week 1 & Week 10
Change in Irritability
The Irritability subscale of the Aberrant Behavior Checklist, Second Edition (ABC-2) measures behaviors associated with irritability, including aggression, self-injury, tantrums, and mood instability. The subscale consists of 15 items, with total scores ranging from 0-45. Higher scores indicate greater irritability and more severe behavioral difficulties, while lower scores indicate less irritability and better behavioral functioning. Items are rated based on the presence and severity of behaviors, and item scores are summed to produce the subscale score.
Time frame: Week 1 & Week 10
Change in Emotional Reactivity
The Emotional Reactivity subscale of the Emotion Dysregulation Inventory (EDI) measures the tendency to experience intense, rapidly escalating, and prolonged negative emotional responses. T-scores are standardized scores derived from the raw Emotional Reactivity score and have a mean of 50 and standard deviation of 10 in the normative sample. Higher T-scores indicate greater emotional reactivity and more severe emotion dysregulation, while lower T-scores indicate less emotional reactivity and better emotional regulation.
Time frame: Week 1 & Week 10
Change in Dysphoria
The Dysphoria subscale of the Emotion Dysregulation Inventory (EDI) measures symptoms of negative mood, including sadness, hopelessness, and emotional distress. T-scores are standardized scores derived from the raw Dysphoria score and have a mean of 50 and standard deviation of 10 in the normative sample. Higher T-scores indicate greater dysphoria and more severe negative mood symptoms, while lower T-scores indicate less dysphoria and better emotional well-being.
Time frame: Week 1 & Week 10
Change in Concentration of Salivary Cortisol
Change in Concentration of Salivary Cortisol from before-session, after-session, and 20 mins after-session. Saliva samples from Weeks 2, 6, and 10 at pre-session, post-session, and post-session +20, were assayed for cortisol content and included in the linear mixed model analyses.
Time frame: Pre-session, Post-session, Post-session + 20 min, averaged across Intervention Weeks 2, 6 and 10
Change in Concentration of Salivary Alpha-amylase
Change in concentration of salivary alpha-amylase from before-session, during-session, and 20 mins after-session. Saliva samples from Weeks 2, 6, and 10 at pre-session, within-session, and post-session +20, were assayed for alpha-amylase content and included in the linear mixed model analyses.
Time frame: Pre-session, Within-session, Post-session + 20 min, averaged across Intervention Weeks 2, 6 and 10
Emotional Awareness Goal Attainment
Attainment of individualized emotional awareness goal. Goal attainment scales range from -2 to +2 where higher values indicate greater progress towards individual goal, level 0 indicates goal was met.
Time frame: Week 10
Self-regulation Tool Identification Goal Attainment
Attainment of individualized goal related to identifying self-regulation tools. Goal attainment scales range from -2 to +2 where higher values indicate greater progress towards individual goal, level 0 indicates goal was met.
Time frame: Week 10
Self-regulation Tool Use Goal Attainment
Attainment of individualized goal related to using self-regulation tools. Goal attainment scales range from -2 to +2 where higher values indicate greater progress towards individual goal, level 0 indicates goal was met.
Time frame: Week 10
We recruited participants via flyers distributed via email listservs and at local events for disability/autism communities.
| Milestone | Occupational Therapy Integrating Horses | Occupational Therapy in a Clinic |
|---|---|---|
| Started | 34 | 38 |
| Completed | 32 | 24 |
| Not completed | 2 | 14 |
| Withdrew: Withdrawal by subject | 2 | 14 |
The Hyperactivity subscale of the Aberrant Behavior Checklist, Second Edition (ABC-2) measures parent/caregiver-reported hyperactive and impulsive behaviors, including excessive activity, impulsivity, and difficulty remaining still or attending. The subscale consists of 16 items, with total scores ranging from 0-48. Higher scores indicate greater hyperactivity and more severe behavioral difficulties, while lower scores indicate less hyperactivity and better behavioral functioning. Item scores are summed to produce the subscale score.
| Scores on a Scale | Occupational Therapy Integrating Horses | Occupational Therapy in a Clinic |
|---|---|---|
| Week 1 Hyperactivity | 25.09 (21.67 to 28.50) | 22.98 (19.19 to 26.77) |
| Week 10 Hyperactivity | 19.71 (16.29 to 23.12) | 19.99 (16.12 to 23.86) |
The Irritability subscale of the Aberrant Behavior Checklist, Second Edition (ABC-2) measures behaviors associated with irritability, including aggression, self-injury, tantrums, and mood instability. The subscale consists of 15 items, with total scores ranging from 0-45. Higher scores indicate greater irritability and more severe behavioral difficulties, while lower scores indicate less irritability and better behavioral functioning. Items are rated based on the presence and severity of behaviors, and item scores are summed to produce the subscale score.
| Scores on a Scale | Occupational Therapy Integrating Horses | Occupational Therapy in a Clinic |
|---|---|---|
| Week 1 Irritability | 18.72 (16.09 to 21.34) | 17.69 (14.78 to 20.60) |
| Week 10 Irritability | 14.87 (12.25 to 17.5) | 13.76 (10.76 to 16.76) |
The Emotional Reactivity subscale of the Emotion Dysregulation Inventory (EDI) measures the tendency to experience intense, rapidly escalating, and prolonged negative emotional responses. T-scores are standardized scores derived from the raw Emotional Reactivity score and have a mean of 50 and standard deviation of 10 in the normative sample. Higher T-scores indicate greater emotional reactivity and more severe emotion dysregulation, while lower T-scores indicate less emotional reactivity and better emotional regulation.
| Scores on a scale | Occupational Therapy Integrating Horses | Occupational Therapy in a Clinic |
|---|---|---|
| Week 1 Emotional Reactivity | 66.60 (64.51 to 68.69) | 64.47 (62.15 to 66.79) |
| Week 10 Emotional Reactivity | 61.72 (59.62 to 63.81) | 61.63 (59.23 to 64.02) |
The Dysphoria subscale of the Emotion Dysregulation Inventory (EDI) measures symptoms of negative mood, including sadness, hopelessness, and emotional distress. T-scores are standardized scores derived from the raw Dysphoria score and have a mean of 50 and standard deviation of 10 in the normative sample. Higher T-scores indicate greater dysphoria and more severe negative mood symptoms, while lower T-scores indicate less dysphoria and better emotional well-being.
| Scores on a Scale | Occupational Therapy Integrating Horses | Occupational Therapy in a Clinic |
|---|---|---|
| Week 1 Dysphoria | 60.24 (57.40 to 63.07) | 56.38 (53.24 to 59.53) |
| Week 10 Emotional Reactivity | 56.43 (53.59 to 59.26) | 53.50 (50.27 to 56.74) |
Change in Concentration of Salivary Cortisol from before-session, after-session, and 20 mins after-session. Saliva samples from Weeks 2, 6, and 10 at pre-session, post-session, and post-session +20, were assayed for cortisol content and included in the linear mixed model analyses.
| ug/dL | Occupational Therapy Integrating Horses | Occupational Therapy in a Clinic |
|---|---|---|
| Pre-session | 0.17 (0.14 to 0.20) | 0.16 (0.13 to 0.19) |
| Post-session | 0.11 (0.10 to 0.13) | 0.13 (0.10 to 0.15) |
| Post-session + 20 min | 0.11 (0.09 to 0.13) | 0.14 (0.11 to 0.16) |
Change in concentration of salivary alpha-amylase from before-session, during-session, and 20 mins after-session. Saliva samples from Weeks 2, 6, and 10 at pre-session, within-session, and post-session +20, were assayed for alpha-amylase content and included in the linear mixed model analyses.
| U/mL | Occupational Therapy Integrating Horses | Occupational Therapy in a Clinic |
|---|---|---|
| Pre-session | 79.57 (60.91 to 103.95) | 51.48 (37.82 to 70.08) |
| Within-session | 79.57 (60.91 to 103.95) | 63.00 (46.28 to 85.76) |
| Post-session + 20 min | 69.47 (53.19 to 90.74) | 56.00 (41.13 to 76.24) |
Attainment of individualized emotional awareness goal. Goal attainment scales range from -2 to +2 where higher values indicate greater progress towards individual goal, level 0 indicates goal was met.
| Proportion of Participants Who Met Goal | Occupational Therapy Integrating Horses | Occupational Therapy in a Clinic |
|---|---|---|
| Emotional Awareness Goal Attainment | 0.719 | 0.696 |
Attainment of individualized goal related to identifying self-regulation tools. Goal attainment scales range from -2 to +2 where higher values indicate greater progress towards individual goal, level 0 indicates goal was met.
| Proportion of Participants Who Met Goal | Occupational Therapy Integrating Horses | Occupational Therapy in a Clinic |
|---|---|---|
| Self-regulation Tool Identification Goal Attainment | 0.935 | 0.652 |
Attainment of individualized goal related to using self-regulation tools. Goal attainment scales range from -2 to +2 where higher values indicate greater progress towards individual goal, level 0 indicates goal was met.
| Proportion of Participants Who Met Goal | Occupational Therapy Integrating Horses | Occupational Therapy in a Clinic |
|---|---|---|
| Self-regulation Tool Use Goal Attainment | 0.719 | 0.609 |
Collected over From Week 1 to follow-up phone call that occurred up to 2-weeks after Week 10.. Non-serious events are listed at a 5% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Occupational Therapy Integrating Horses | 0/32 (0%) | 0/32 (0%) | 2/32 (6.3%) |
| Occupational Therapy in a Clinic | 0/24 (0%) | 0/24 (0%) | 1/24 (4.2%) |
| Event | Occupational Therapy Integrating Horses | Occupational Therapy in a Clinic |
|---|---|---|
| Emotional Upset During TherapyGeneral disorders | 2/32 | 1/24 |
Some participants (OT-Equine n=2; OT-Clinic n=12) withdrew after randomization prior to baseline assessments.
| Age, Continuous(Years) | Occupational Therapy Integrating Horses | Occupational Therapy in a Clinic | Total |
|---|---|---|---|
| Mean | 8.7 ± 1.7 | 9.2 ± 1.7 | 8.9 ± 1.7 |
| Sex: Female, Male(Participants) | Occupational Therapy Integrating Horses | Occupational Therapy in a Clinic | Total |
|---|---|---|---|
| Female | 10 | 8 | 18 |
| Male | 22 | 18 | 40 |
| Race (NIH/OMB)(Participants) | Occupational Therapy Integrating Horses | Occupational Therapy in a Clinic | Total |
|---|---|---|---|
| American Indian or Alaska Native | 0 | 0 | 0 |
| Asian | 4 | 0 | 4 |
| Native Hawaiian or Other Pacific Islander | 0 | 0 | 0 |
| Black or African American | 1 | 1 | 2 |
| White | 20 | 18 | 38 |
| More than one race | 5 | 5 | 10 |
| Unknown or Not Reported | 2 | 2 | 4 |
| Ethnicity (NIH/OMB)(Participants) | Occupational Therapy Integrating Horses | Occupational Therapy in a Clinic | Total |
|---|---|---|---|
| Hispanic or Latino | 7 | 7 | 14 |
| Not Hispanic or Latino | 25 | 19 | 44 |
| Unknown or Not Reported | 0 | 0 | 0 |
| ABAS-3 General Adaptive Composite(Score on a Scale) | Occupational Therapy Integrating Horses | Occupational Therapy in a Clinic | Total |
|---|---|---|---|
| Mean | 79.8 ± 8.8 | 75.4 ± 8.8 | 77.9 ± 9.0 |
PDFs hosted by the registry, ClinicalTrials.gov.
Plan to share: Yes — De-identified data will be shared in an appropriate data repository, such as the "Data and Specimen Hub" (DASH) or the "National Database for Autism Research" (NDAR). Data will be shared no later than the acceptance for publication of the main findings from the final dataset. Salimetrics will discard saliva samples after testing, and therefore saliva samples will not be available for sharing.
Supporting information: Informed consent form
Time frame: We will share in an appropriate data repository indefinitely, no later than the acceptance for publication of the main findings from the final dataset
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