PROJECT SUMMARY/ABSTRACT Fetal alcohol spectrum disorders (FASD) are a highly prevalent neurodevelopmental disability yet extremely underserved by systems of care. FASD is linked to varying abilities in areas of executive function, attention, memory, adaptive skills, and emotion regulation. These emotion regulation difficulties are associated with 90% of individuals with FASD having co-occurring mental health disorders. However, no evidence-based mental health treatments have been adapted or tested for this population. This gap is particularly salient for the adolescent period, as many of these co- occurring disorders arise during this developmental timeframe. Dialectical behavior therapy for adolescents (DBT-A) is an evidence-based cognitive-behavioral therapy that specifically targets the biological predisposition for emotion dysregulation and invalidating environments that adolescents with FASD commonly experience. DBT-A is an intensive treatment program, involving weekly skills groups with adolescents and their caregivers, weekly individual therapy for adolescents, and 24/7 phone coaching. The proposed project aims to adapt DBT-A for adolescents with FASD and their caregivers and test the feasibility of the adaptations in a community mental health clinic. Given low FASD awareness among community clinicians, this project will also involve the development of trainings for mental health clinicians on FASD. Implementation science, specifically the EPIS framework (Exploration, Preparation, Implementation, Sustainment) and attention to social determinants of health will guide the conduct of the project. Input from a community advisory board consisting of adolescents with FASD, caregivers, and mental health clinicians will be prioritized at every step of the EPIS process. The aims of the proposed project are as follows: Aim 1- Systematically develop materials for FASD-informed DBT-A administration utilizing the EPIS implementation framework; Aim 2 - Conduct a feasibility trial of DBT-A with adolescents with FASD and their primary caregiver. The proposed project is an essential foundational step to address the gap in mental health care for individuals with FASD, as well as assist mental health clinicians in best serving this population. The feasibility of this project is supported by emerging research adapting DBT to other populations with neurodevelopmental difficulties. As this project will take place in an existing clinic in the community, it allows for careful examination of implementation factors that could support future generalizability to other existing mental health clinics. Additionally, the proposed project will provide mentored training to prepare the PI for a career as an independent researcher. Through the support and guidance of experts in the fields of FASD, intervention, implementation science, DBT, and social determinants of health, the PI will gain essential competencies in mental health intervention development, rigorous implem...