Table 2 Study measures

 Attitudes

Social Distance Scale (SDS)^{A, C}: explicit stigmatizing attitudes questionnaire [42] widely used in mental health [78] in global stigma comparisons [79]; the Nepali version has 12 self-report questions on a scale of 1 to 6 and three vignettes (depression, psychosis, and alcohol use disorder); Nepal α = 0.90. Primary outcome for objective 1; mediator for objective 2. PCP_T0,T1,T2,T3.

Implicit Association Test (IAT)^B: implicit biases against mental illness; tablet-administered test: mental health version has been used in numerous high-resource settings [80,81,82,83]; in Nepal, we developed two versions: mental illness vs. harmfulness and mental illness vs. burdensomeness; administration time is 15 min. PCP_T0,T1,T2,T3.

 Behavioral intentions

Reported and Intended Behavior Scale (RIBS)^B: 8-item scale to measure the behavioral intentions towards people with mental health problems [84]. PCP_T0,T1,T2,T3.

 Knowledge

mhGAP Knowledge^{B, C}: 31 multiple-choice questions for diagnostic and treatment knowledge; globally used for mhGAP trainings [85,86,87]. PCP_T0,T1,T2,T3.

 Competency and quality

Enhancing Assessment of Common Therapeutic factors (ENACT)^{B, C}: observed structured clinical exam; health workers conduct a 10-min role-play with standardized patients; 15 items for common factors, 5 items for mhGAP assessment competencies, and 2 items for recommended diagnosis and treatment; developed in Nepal [88, 89]; α = 0.89; administered through the World Health Organization Ensuring Quality in Psychological Support (EQUIP) platform [90]. PCP_T0,T1,T2,T3.

 Self-efficacy

mhGAP Clinical Self-Efficacy^B: 38 self-reported ability to diagnose and treat mental illness; standard mhGAP assessment; widely used globally [85,86,87]; Nepal α = 0.99. PCP_T0,T1,T2,T3.

 Accurate diagnosis

Structured Clinical Interview for DSM-5-Clinical Trials Version (SCID-5-CV)^A: psychiatrist interview for diagnostic accuracy [91]; SCID for DSM-IV previously used in Nepal showing strong concordance with Composite International Diagnostic Interview [92]; accurate diagnosis is used as a proxy for reach of services. Primary (implementation) outcome for objective 2. PT_T1.

 Functioning

WHO Disability Assessment Schedule (WHODAS)^B: self or caregiver report of functional impairment with 13 fixed response questions and 3 open-ended related timing [93]; widely used in Nepal [61, 70, 94,95,96]; Nepal α = 0.87. PT_T0,T1,T2.

 Quality of life

EQ-5D-5L^B: 5-item self or caregiver report of quality of life years (QALYs) based on 5 dimensions: mobility, self-care, daily activities, pain/discomfort, and mood (anxiety/depression); official EuroQol translation available for Nepal; Asian utility weights available from Thailand [97]. PT_T0,T1,T2.

 Psychiatric symptom severity

Patient Health Questionnaire (PHQ9)^B: 9-item assessment of depression symptoms and 1-item impact on functioning [98]; validated in a primary care setting in Nepal, with the addition of a local idiom of distress “heart-mind problems” [67]; validated Nepal cutoff  ≥ 10: sensitivity = 94%, specificity = 80%; α = 0.84. PT_T0,T1,T2.

Generalized Anxiety Disorder (GAD-7)^B: 7-item assessment of anxiety symptoms, structured in the same format as the PHQ-9. Previously used in Nepal [99,100,101]. PT_T0,T1,T2.

Positive and Negative Syndrome Scale (PANSS)^B: assessment of positive and negative symptoms of psychosis, designed for schizophrenia symptom severity [102]; in Nepal, adapted for self- or caregiver report [94], adapted scoring cutoff > 10, sensitivity = 90%, positive items α = 0.82, negative items α = 0.88; combined α = 0.89. PT_T0,T1,T2.

Alcohol Use Disorder Identification Test (AUDIT)^B: 13-item assessment of the quantity of alcohol consumption, tolerance, and dependence [103]; validated in a medical setting in Nepal [104]; cutoff ≥ 9, sensitivity 96.7% for males and 94.37% for females, specificity 79.6% and 85.4%, respectively; α = 0.82. PT_T0,T1,T2.

 Competency of provider

Enhancing Assessment of Common Therapeutic factors (ENACT)-Patient version^B: 12-item patient version of the ENACT scale that allows patient and/or caregiver to comment on therapeutic rapport, comprehensiveness of mental health evaluation, and communication skills; developed in Nepal and shown to associate with depression treatment outcomes [105]. This is also an indicator of a positive experience of care [106]. PT_T2.

 Stigma and discrimination

Discrimination and Stigma Scale Short Version (DISCUS)^B: 11-item scale to measure discrimination and stigma experienced by people with mental health problems [107]. PT_T2.

Internalized Stigma of Mental Illness (ISMI)^B: 29-item scale used to measure internalized stigma among people with mental health problems [108]. PT_T2.

 Barriers to care

Barriers to Access to Care Evaluation (BACE)^B: stigma and other barriers to accessing health services [109], adapted and used in rural Nepal n = 324 [47]. PT_T2.

 Cost of care

Client Service Receipt Inventory (CSRI)^B: costs associated with psychiatric interventions [110]; records information on employment earnings and benefits, hospital care, primary care, social care, and support from informal caregivers (e.g., family); previously used in Nepal [111]. The period covered for costs will be from enrollment in the health facility onward until the assessment point (i.e., 0–3 months; 3–6 months). PT_T1,T2.