This Arm is a 10 week one hour small group (2-4 participants) led by a THR instructor. The group will include a 45-minute mounted activity to learn horsemanship skills as outlined in the study's THR manual, . Group times will be between 1:00-5:00 PM to collect salivary cortisol. Weekly, participants will follow a consistent routine of wearing both their electro dermal activity and heart rate monitoring devices, sit at a group art table before class, after this, study personnel will instruct participants to place the 10cm long foam swab rod under their tongue for one minute while watching a 1-minute timer. Participants will then don their riding helmets and enter the riding arena. Each week after conclusion of the THR intervention, participants will again sit with their group at an art table for 5 minutes followed by doing another saliva sample.

This Arm is a 10 week one hour small group (2-4 participants) led by a THR instructor and co-led by a mental health or Occupational therapy provider. Participants will have one assigned volunteer and will have no physical contact with horses at the riding center, just view horses from a distance. There will be a life-sized stuffed toy horse for hands-on learning related to the weekly topic per the BA study manual. Group times will be between 1:00-5:00 PM to collect salivary cortisol. Weekly, participants will follow a consistent routine of wearing both their electro dermal activity and heart rate monitoring devices, sit at a group art table before class, after this, study personnel will instruct participants to place the 10cm long foam swab rod under their tongue for one minute while watching a 1-minute timer. Each week after conclusion of the BA intervention, participants will again sit with their group at an art table for 5 minutes followed by doing another saliva sample.

Horse therapy

58-item symptom presence and severity (0-3, not a problem to severe problem) checklist of problem behaviors of children and adults with developmental disabilities in community settings. The 58 items resolve into five subscales: (1) Irritability, Agitation, (2) Lethargy, Social Withdrawal, (3) Stereotypic Behavior, (4) Hyperactivity, and (5) Inappropriate Speech.Irritability and Hyperactivity behaviors

social awareness, social cognition, social communication, social motivation, autistic mannerisms. Results in a T-score that indicates severity level ranges.

24 -item Reactivity behaviors of intense, rapidly escalating, sustained, and poorly regulated negative emotional reactions, and 6-item Dysphoria behaviors of minimal positive affect and motivation, and the presence of nervousness and sadness.Both the Dysphoria Scale and Reactivity Short Form have IRT-based theta scores, which have a mean of 0 and SD of 1, and provide superior discriminative ability to raw scores.

Quality of life for caregiver

Expressive Language Sample

Mediator

Change in skin conductance will be reported. Electrodes will be attached to the underside of the wrist of their non-dominant hand to record electrodermal activity (EDA). EDA measures individual differences in endocrine sweat gland activity.