Project Summary/Abstract The primary objective of this R01 application is to evaluate the potential additive effect of animal-assisted intervention (AAI) on a manualized behavioral treatment targeting emotion dysregulation (ED) in children with autism spectrum disorder (ASD). ED in youth with ASD has been linked to significantly higher rates of psychiatric hospitalizations, suicidal ideation, use of psychotropic medications, school disciplinary actions, peer rejection, failed college and employment transitions, and poorer quality of life. Our group developed Regulating Together (RT), an intensive group-based treatment with a concurrent parent group that employs evidence-based intervention techniques of cognitive behavioral therapy, parent training, and mindfulness and acceptance-based therapy. Preliminary evidence for its feasibility and efficacy has been demonstrated, including reductions in emotional reactivity and dysphoria and increases in heart rate variability and cognitive flexibility at 10-weeks following intervention. Despite this, change did not occur immediately post intervention. Animal Assisted Interventions (AAI) have emerged as a promising approach for youth with ASD, demonstrating improvements in irritability, hyperactivity, positive affect, and quality of life. AAI also has shown to increase in-session engagement and learning. Yet, AAI has not yet been utilized to systematically target ED in ASD nor has it been examined in conjunction with a manualized intervention. In the current study, we propose a multi-site randomized clinical trial of RT with and without a canine present to evaluate its immediate and longer-term efficacy. In 240 youth (ages 8-12 years) with ASD, we will assess RT with AAI (RT-Canine) and without AAI (RT-Standard) on primary ED symptom of reactivity, and secondary outcomes, including dysphoria, caregiver stress, cognitive flexibility, mindfulness awareness, and emotion regulation skills knowledge. We hypothesize that the canines will increase therapeutic engagement measured through alliance, motivation, and improved behavior, which will then increase intervention session level learning, and ultimately immediate and long-term intervention outcomes. Furthermore, based on our preliminary evidence, we also will explore an objective outcomes measure of heart rate/heart rate variability and its relationship to engagement, learning, and ED symptom outcomes. This proposal is relevant to the NICHD Human-Animal Interaction funding opportunity by addressing the critical public health issue of ASD through examination of AAI efficacy by utilizing standardized data collection outcome methods. In addition, we closely address protection for both the canines and the youth with ASD throughout the proposal. Finally, we will make a concerted effort to include youth from minority groups, as emphasized in the FOA. Ultimately, findings from our study have the potential to expand both ASD and AAI research, with immense impact on ...