Comparative Effectiveness of Therapeutic Riding and Stress Management Program on Salivary Cortisol and Heart Rate Variability of Youth on the Autism Spectrum

Background: For youth who are transitioning into adulthood with autism spectrum disorder (ASD), elevated stress levels and lack of coping mechanisms (Plessow, Fischer, Kirschbaum, & Goschke, 2011) relating to the core symptoms of autism become barriers to health and wellness (Hong, Bishop-Fitzpatrick, Smith, Greenberg, & Mailick, 2016). Limited research with younger children, ages 5-15, suggests that therapeutic riding (TR) improves gross motor and postural skills (Hawkins, Ryan, Cory, & Donaldson, 2014), spontaneous verbalization (Holm et al., 2014), irritability, hyperactivity, social cognition, and receptive communication skills (Ajzenman, Standeven, & Shurtleff , 2013) as well as quality-of-life (Lanning, Baier, Ivey-Hatz, Krenek, & Tubbs, 2014). A paucity of research exists with regard to young adults (from 14-25) and the impact of TR on emotional regulation or stress level (O’Haire, 2012).

Objectives: The research question concerns the comparative effectiveness of stress management (SM) techniques and Therapeutic Riding (TR) on stress levels of adolescents with ASD. The objective was to better understand the impact of TR and SM program as compared to a control phase in the same adolescent.

Methods: The study compares an evidence-based stress management protocol (HeartMath) to a TR protocol to no treatment control for 27 young adults ages 13-22 with ASD in a randomized three-period crossover trial. All interventions were one hour in length for ten consecutive sessions and administered by the same CTRS with a certification appropriate to the intervention (PATH or HeartMath certification). Participants were randomly assigned to the order in which they receive TR, HeartMath (HM), and no treatment control. Before and after each of the three 10-week periods, self-reported stress levels (Cohen et al., 1983) and salivary cortisol levels were measured. Salivary cortisol was measured over two consecutive days at four time points (Rising, 30 minutes after, session, and bedtime). Cortisol levels were also measured before and after each intervention session. Heart rate variability (HRV) was measured during each session using an emwave Pro sensor. Multivariate analysis of variance with one within-groups factor (time) and between-groups factors (TR vs. HM vs. control) was used.

Results: Analysis revealed a greater difference (p <.05) of self-reported stress in the TR phase than the HM phase. Coherence levels (HVR) were higher during the HM stress management sessions than TR sessions. There was a statistically significant decrease (p < .05) between the pre to post mean cortisol values for TR sessions and HM sessions. While the mean difference scores between pre and post TR cortisol are larger than mean difference scores for HM, no statistically significant difference exists (p = .17). When comparing mean baseline to follow-up for TR to control, cortisol was reduced during the 30 minutes post awakening in the therapeutic riding. Further analysis will be focused on trends in individual response over phases.

Conclusions: While it is temporary, TR and HM are equally beneficial in decreasing cortisol levels. Both programs are more effective in decreasing salivary cortisol and self-reported stress than a period without intervention. For adolescents with ASD, pre-screening may determine the more effective intervention.