Testing the Feasibility of a Family-based Adjunctive Treatment Protocol for Targeting Co-Occurring Internalizing Disorders among Adolescents with SUD - Project Summary (Abstract) This R34 will develop and test an adjunctive treatment protocol for addressing co-occurring internalizing disorders among adolescents (age 13-21) enrolled in usual care for substance use problems. Internalizing disorders (IDs), primarily depression and anxiety, are highly prevalent among youth receiving community-based treatment for substance use disorders (SUDs), and unresolved ID issues significantly interfere with SUD treatment and recovery processes. Yet, the youth SUD clinical workforce is not systematically educated or trained in evidence-based practices for ID; thus, line services for youth SUD do not systematically target IDs. The research literature offers a few integrated behavioral models for simultaneously treating both SUDs and IDs in youth; however, such models feature intensive manualized procedures that have proven cumbersome to scale and deliver in frontline settings. As a result, the clinical workforce, though desiring ID-focused training, currently has inadequate resources for treating IDs effectively. A promising solution to reduce this quality gap is developing a modular, family-based protocol to augment routine care for comorbid SUD/ID by directly targeting ID as a primary treatment goal: Family Support Protocol for Adolescent Internalizing Disorders (Fam-AID). Fam-AID will contain six modules designed to enhance existing SUD services and to be delivered in any sequence to meet client needs: (1) Family Engagement of caregivers in treatment planning and services; (2) Relational Reframing of family constraints, resiliencies, and social capital connected to the youth's ID symptoms; (3) Functional Analysis of the youth's ID symptoms and related behaviors; (4) Core cognitive-behavioral treatment techniques to address the youth's ID symptoms and functional needs, featuring transdiagnostic interventions (emotion acceptance, emotional exposure, behavioral activation) to address negative affect and emotional dysregulation underlying both depression and anxiety; (5) Family Psychoeducation and Safety Planning focused on education about comorbid SUD/ID and prevention of youth self-harm. The study will follow the NIDA blueprint for Stage 1 development of behavioral protocols. In the Pilot Stage we will use rapid cycle prototyping methods in collaboration with end-user stakeholders at two Pilot sites to: (1) Draft protocol delivery and fidelity guidelines adapted from existing study team resources; (2) Solicit clinic staff and client input on protocol content and delivery via cognitive interviewing; (3) Pilot the prototype components on 2-3 cases at each site. We will then conduct an Interrupted Time Series Study for N = 60 comorbid SUD/ID cases across two sites serving diverse youth: 30 will receive TAU (historical control), and then following line staff training in the protocol, 30 new cases will receive TAU enhanced by Fam- AID. Aim 1 will examine Fam-AID cases for protocol acceptability via therapist and client interviews and fidelity benchmarks via therapist- and observer-report protocol fidelity data. Aim 2 will compare Fam-AID versus TAU for immediate outcomes on family attendance in sessions and ultimate outcomes on youth ID symptoms at Baseline, 3-, and 6-month follow-up.