Neurodevelopmental disorders of Attention-Deficit/ Hyperactivity Disorder (ADHD) and Oppositional Defiant Disorder (ODD) are extremely common but underserved with Evidence- Based Treatments (EBT) worldwide. Thus, a school clinician training and ADHD/ODD intervention (i.e., the Collaborative Life Skills [CLS] program) was developed, implemented and evaluated for Mexico: a setting with high unmet need. Technology was integrated into the in-person program (CLS-FUERTE) to create a digitally enhanced version (CLS-R-FUERTE). Given findings demonstrating feasibility, acceptability, and efficacy of both program versions, a Type 2 Hybrid Effectiveness-Implementation Design will be applied to evaluate the program effectiveness, mechanisms of intervention change, and maintenance barriers/facilitators in a scaled-up cluster randomized controlled trial across two Mexican states -while simultaneously exploring an implementation strategy in which the program is adapted to enhance maintenance given each school's needs/resources (i.e., CLS-A-FUERTE). The implementation process is guided by the Exploration, Preparation, Implementation, and Sustainment (EPIS) model with evaluation following the Reach, Effectiveness, Adoption, Implementation, and Maintenance (RE-AIM) Framework.

Aim 1) Test the effectiveness and implementation of the CLS-A-FUERTE school clinician training and ADHD/ODD intervention program adapted for schools across Mexico. It is predicted:

H1) School clinicians will engage in training and implement chosen intervention components with fidelity H2) Teachers and/or families will engage in chosen intervention components and adhere to the strategies H3) Students receiving the CLS-A-FUERTE intervention will show greater improvements in ADHD/ODD symptoms and associated impairment compared to students receiving school services as usual

Aim 2) Evaluate mechanisms of sustained intervention change. It is predicted:

H4) Improvements in parenting behaviors will mediate sustained intervention effects H5) Improvements in teacher and/or school clinician competency will mediate intervention effects

Aim 3) Identify CLS-A-FUERTE maintenance barriers and facilitators. It is predicted that sustained intervention effects and continuation of program activities at follow-up will relate to:

H6) Program feasibility (i.e., cost estimates) and acceptability (i.e., participant satisfaction) H7) Characteristics of participating schools and school context factors

Aim 4) Expand research capacity to a novel university setting. It is predicted that emerging investigators will:

H8) Complete clinical research coursework and produce deliverables (i.e., presentations, papers, grants) H9) Show improved EBT skills, research capacity and culture ratings, and competency as program trainers

Inclusion Criteria:

• must demonstrate at least six inattention symptoms and/or six hyperactive/impulsive symptoms endorsed by parent or teacher as occurring often or very often, AND at least one area of impairment rated as concerning by both parent and teacher, AND have a parent and teacher agreeing to participate (for student participants)
• Must be a parents, teacher, or school clinicians of participating students (for parent, teacher, and school clinician participants)
• Must be a university student in psychology or education at UAS or BUAP (for emerging investigator/university student participants)

Exclusion Criteria:

• inability to speak and read Spanish
• unstable medication regimen (for student participants)
• severe visual or hearing impairment (for student participants)
• severe language delay (for student participants)
• psychosis (for student participants)
• Placement in an all-day special education classroom (for student participants)