Case Presentations Combining Family-Based Treatment with the Unified Protocols for Transdiagnostic Treatment of Emotional Disorders in Children and Adolescents for Comorbid Avoidant Restrictive Food Intake Disorder and Autism Spectrum Disorder.

Avoidant Restrictive Food Intake Disorder (ARFID) is a Feeding and Eating Disorder newly added to the Diagnostic and Statistical Manual of Mental Disorders, 5 ^th Edition, which presents with high prevalence rates in community and clinical settings. Given its recent diagnostic recognition, validated and standardized treatments for this population are lacking. In addition, given the complexity, heterogeneity of symptoms, and high rates of psychiatric comorbidities in the ARFID population, new models of care are required. The current therapy model combines two evidence-based treatments - Family Based Treatment (FBT) and the Unified Protocols for Transdiagnostic Treatment of Emotional Disorders in Children and Adolescents (UP-C/A) - for young patients with ARFID plus Autism Spectrum Disorder (ASD), which allows clinicians to personalize care based on each patient's unique presenting needs. This paper presents two distinct cases which showcase the use of the FBT+UP for ARFID approach for treating comorbid ARFID and ASD in a clinical setting. Case 1 demonstrates the application and reliance on FBT, while Case 2 draws upon UP to facilitate behavioural change in the patient. Case backgrounds, presenting problems, and treatment approaches combining the two evidence-based treatments are presented and discussed. The cases demonstrate the unique challenges of treating young patients with comorbid ARFID and ASD, along with the proposed benefits of the combined approach with this population.