AGENCIA In-person With Digital Assistant is a brief, structured psychological intervention aimed at strengthening personal agency and improving emotional and behavioral functioning in adolescents. It consists of three core sessions addressing emotion regulation, self-compassion, value-based actions, meaningful goal pursuit, and the reduction of family accommodation. In the in-person format, a mental health professional delivers the intervention in person, while a conversational digital assistant guides structured exercises and presents session content. The clinician supervises and ensures safe, consistent delivery. The therapeutic ingredients and objectives of AGENCIA remain identical to those used in the self-guided format.

Index of functional impairment associated with emotional and behavioral symptoms, including impact on home life, friendships, school learning, and overall distress, measured with the Strengths and Difficulties Questionnaire Impact Supplement. The impact score ranges from 0 to 10, with higher scores indicating greater impairment.

Measures irritability, lethargy/withdrawal, stereotypy, hyperactivity/non-compliance, and inappropriate speech using the Aberrant Behavior Checklist. The ABC consists of 58 items across 5 subscales, each scored from 0 (not a problem) to 3 (severe problem). Subscale score ranges are: Irritability (0-45), Lethargy/Social Withdrawal (0-48), Stereotypic Behavior (0-21), Hyperactivity/Noncompliance (0-48), and Inappropriate Speech (0-12). Higher scores indicate more severe symptoms.

Self-reported global functioning across emotional, behavioral, social, and daily living domains measured with the Health of the Nation Outcome Scales for Children and Adolescents - Self-Rated (HoNOSCA-SR). The scale consists of 13 items, each rated from 0 to 4. The total score ranges from 0 to 52, with higher scores indicating greater impairment.

Health-related quality of life index measured with the EuroQol 5-Dimension 5-Level questionnaire, covering mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. The index score is calculated using country-specific value sets and ranges from less than 0 (states worse than dead) to 1.0 (perfect health), with higher scores reflecting better health status.

Extent to which caregivers or adolescents engage in accommodation behaviors that may maintain emotional/behavioral difficulties, measured with the Family Accommodation Scale - Anxiety (FASA) for parents and FASA-Child Report (FASA-CR) for adolescents. The FASA total score ranges from 0 to 36, with higher scores indicating more accommodation.

Assesses adolescents' sense of personal agency (ability to initiate and sustain goal-directed actions) using the Children's Hope Scale - Agency Subscale. The agency subscale consists of 3 items, each rated from 1 to 6, yielding a subscale score range of 3 to 18, with higher scores indicating stronger perceived agency.

Self-reported ratings of satisfaction with the intervention, ease of use, perceived helpfulness, and likelihood of recommending it, measured with an ad hoc Usability and Satisfaction Questionnaire developed for this study. The questionnaire includes 7 closed-ended items assessing perceived benefit, treatment planning, motivation to use strategies, likelihood of recommendation, and modality-specific usability (digital platform, in-person, or conversational AI agent). Each item is rated on a 4-point scale (0 = No, 1 = A little, 2 = Yes, 3 = Very much). Individual item scores range from 0 to 3, with higher scores indicating greater usability, acceptability, and satisfaction. The questionnaire also includes one open-ended item for qualitative feedback.

Relational openness measured with an ad hoc 4-item self-disclosure scale developed for this study, assessing the tendency to talk about oneself, share feelings, express beliefs and opinions, and feel comfortable revealing one's true self during the intervention. Items are adapted to the intervention format (AI conversational agent, therapist-led, or web/app-based). Each item is rated on a 5-point Likert scale (1 = Strongly disagree to 5 = Strongly agree), with total scores ranging from 4 to 20. Higher scores indicate greater relational openness.

Working alliance measured with the Session Rating Scale (SRS), a 4-item visual analog scale assessing relationship bond (feeling heard, understood, and respected), agreement on goals and topics, agreement on approach or method, and overall session quality. Each item is rated on a 0-10 visual analog scale, with total scores ranging from 0 to 40. Higher scores indicate stronger perceived therapeutic alliance.

Adaptive functioning assessed with the Adaptive Behavior Assessment System, Second Edition (ABAS-II), providing a General Adaptive Composite (GAC) and conceptual, social, and practical domain scores. The GAC is a standard score with a normative mean of 100 and standard deviation of 15. Standard scores typically range from 40 to 160, with lower scores indicating poorer adaptive functioning.

Dimensional assessment of autistic traits measured with the Social Responsiveness Scale, Second Edition (SRS-2), used for baseline characterization and heterogeneity analyses. The SRS-2 yields T-scores with a normative mean of 50 and standard deviation of 10. T-scores range from 37 to 90+, with higher scores indicating greater severity of autistic traits. T-scores ≥76 are considered severe, 66-75 moderate, and 60-65 mild.

Emotional and behavioral problems assessed with the Child Behavior Checklist (CBCL), providing broadband Internalizing and Externalizing problem scores and syndrome scales. The CBCL yields T-scores with a normative mean of 50 and standard deviation of 10. T-scores range from approximately 30 to 100, with higher scores indicating greater symptom severity. T-scores ≥64 are considered clinically significant.

Accumulated psychosocial stress measured with the Adolescent Stress Questionnaire-14 (ASQ-14), a 14-item scale assessing exposure to common adolescent stress domains. Each item is rated on a 5-point scale (1 = not at all stressful to 5 = very stressful), with total scores ranging from 14 to 70. Higher scores indicate greater stress burden.

Sociodemographic and clinical information collected for sample characterization and covariate adjustment, including: age, sex assigned at birth, gender identity, racial/ethnic self-identification (White, Black, Roma, Latin American, Arab/Moroccan, Mixed, Asian, other), recruitment source, living situation, educational level and school modality (mainstream, mainstream with support, specific classroom, or special education center), personal neuropsychiatric history (current and past diagnoses), family neuropsychiatric history (first-degree: parents, siblings; second-degree: grandparents, aunts/uncles), current and past psychopharmacological treatments (name, dose, regimen, start/end dates), and history of significant adverse drug reactions (paradoxical reactions to benzodiazepines/sedatives/anesthetics, atypical reactions to other medications). These are descriptive categorical and continuous variables; no composite score is calculated.

Social determinants of health assessed with the THRIVE Screener (Boston Medical Center), a caregiver-reported questionnaire designed to identify social risk factors in clinical settings. The screener includes 9 items covering: housing stability (0 = stable, 1 = at risk, 2 = unstable), food security (2 items; 0 = never, 1 = sometimes, 2 = frequently), medication affordability (Yes/No), transportation access to medical appointments (Yes/No), utility payment difficulties (Yes/No), caregiving burden (Yes/No), employment status (Yes/No), and interest in further education (Yes/No). Items use mixed response formats; higher scores on housing and food security items indicate greater social risk. This measure is used for sample characterization and covariate adjustment; no composite score is calculated.

Height (cm) and weight (kg) collected as general health indicators for sample characterization. These are continuous measurements reported in their respective units.

Electrodermal activity (skin conductance, µS) and heart rate (beats per minute) continuously recorded using an Empathic wristband device during intervention sessions as potential mechanistic correlates of emotional reactivity and autonomic stress response. These are continuous physiological measurements; mean, variability, and reactivity indices may be derived for analysis.