This cluster-randomized hybrid type-II implementation superiority trial will include 14 rural primary care facilities in Madhya Pradesh, which will implement a collaborative depression care packaged based on the WHO mhGAP program. These 14 facilities will be randomized to receive either 'Enhanced Implementation Support' or the existing 'Routine Implementation Support' control condition to determine if Enhanced Implementation Support is superior to Routine Implementation Support for ensuring successful implementation of the depression care package.

Enhanced Implementation Support consists of remote coaching support and technical assistance. The primary implementation outcome is the proportion of outpatients screened on the PHQ-2 by facility staff. Secondary implementation outcomes will also be collected, including the number of depression cases identified, number of patients with depression referred to the medical officer, number of patients referred to an accepted treatment intervention (i.e., either antidepressant medication or brief psychological intervention), and number of patients who successfully complete treatment at follow up. Secondary patient outcomes will also be collected from patients enrolled in each arm. Patient-level outcomes include the proportion of patients who achieve remission (defined as PHQ-9<5) at 3-month follow up. Additional patient-level outcomes include symptoms of anxiety and functioning.

This trial will develop and test an Enhanced Implementation Support strategy for integrating evidence-based mental health services into primary care facilities. Findings from the trial will inform the need to have external coaching for primary care facilities to meet their depression screening and treatment goals, or if they can achieve these goals via routine system support. This is crucial to inform policymakers, due to severe constraints on mental health budgets for programs in India. Findings can generate insights to inform the scale-up of depression care across other districts in Madhya Pradesh and in India.

Evidence-based clinical interventions exist for depression; however, the gap between those who need treatment and those who receive it (i.e., the care gap) is alarming, with upwards of 90% of individuals not having access to care in India. Integrating evidence-based treatments into primary care is essential for ensuring access to mental health services, and ultimately, bridging the care gap. In India, many of these barriers to implementation have emerged from prior efforts to integrate evidence-based depression care into primary care, such as suboptimal organization and planning, and demands for training of staff on evidence-based interventions.

Implementation research seeks to improve the integration of evidence-based treatments into routine practice through the use of "Implementation Strategies". In a recent review by Wagenaar et al (2020) on implementation strategies for depression care in low- and middle-income countries, it was found that approximately half of these studies were focused on testing revised professional roles, or task-shifting, for depression intervention implementation. In this review, six studies from India examined the integration, acceptability, feasibility and cost of integrating depression care in routine primary care settings, but only one of these studies had a randomized controlled trial design. There is a need to conduct studies with pragmatic designs to examine the effectiveness and cost-effectiveness of integrating evidence-based depression interventions into routine primary care. Moreover, the reviewed studies have scarcely reported on 'adoption' and initial implementation of depression interventions.

This trial aims to address the treatment gap and the structural and contextual factors affecting the optimal implementation of a collaborative care package for depression in primary care settings in Madhya Pradesh, India. Specifically, this study will employ a cluster-randomized controlled design to evaluate whether a 'remote coaching implementation support strategy' compared to 'routine implementation support' can increase rates of screening for depression (i.e., primary implementation outcome). The trial will also assess the successful implementation of the collaborative depression care package via facility-level indicators, including the following secondary implementation outcomes: number of depression cases identified, number of patients with depression referred to the medical officer, number of patients referred to an accepted treatment intervention (i.e., either antidepressant medication or brief psychological intervention), and number of patients who successfully complete treatment at follow up.

Secondary patient outcomes will also be collected from patients enrolled in each arm, including the proportion of patients who achieve remission (defined as PHQ-9<5) at 3-month follow up, given that this reflects a clinically meaningful treatment target. Additional patient-level outcomes include symptoms of anxiety and functioning.

The trial will explore health facility 'readiness' and its relationship with the adoption of the depression care package. Importantly, this trial will employ the routine health facility cadres, such as the auxiliary nurse midwife (ANM) and nurses, primarily for depression screening, and the medical officer (MO) for diagnosis, treatment and referral of cases, and employ routine data collection and management systems. This trial builds on recent health system-level changes in India where screening and management of non-communicable disorders has already been integrated into primary care, creating a template for the integration of evidence-based depression care.

Inclusion Criteria:

• Facilities must be primary health centers in Sehore district, Madhya Pradesh, which have been upgraded to "Health and Wellness Center" status offering services for non-communicable disease care, and that have an Accredited Social Health Activist (ASHA) worker linked to the Health and Wellness Center to ensure access to the brief psychological treatment for depression
• Patients must be outpatients seen at these facilities, and must be adults of any gender age ≥18 years
• Patients must screen positive for depression by the ANM/nurse defined as having a PHQ-2 score ≥3.

Exclusion Criteria:

• Facilities that have not been upgraded to Health and Wellness Center and that do not have a linked ASHA worker
• Patients that have significant speech, hearing, language or cognitive impairment impacting their ability to provide informed consent and complete study assessments
• Patients in need of urgent medical or psychiatric attention (e.g., emergency treatment or in-patient admission)
• Patients who do not plan to stay in the study catchment area for at least three months at the time of consent
• Patients who do not understand Hindi

Individual participant data (IPD) from this trial will be shared with the scientific community according to the National Institute of Mental Health (NIMH) Data Archive Data Sharing terms and conditions. Data will have all direct or indirect identifiable information removed before being submitted to the NIMH Data Archive (NDA). After the trial, the investigators will send de-identified information from participants to NDA. Researchers can access this de-identified data by submitting a request to NIMH. Data sharing with NDA offers no direct benefit to participants, though the information provided to NDA may help researchers around the world treat future mental health challenges so that they have better outcomes. Study participants can choose not to have their de-identified data shared with NDA. These details about data sharing with NDA are described in the participant consent form, and additional information is available at the NDA website.

De-identified individual participant data (IPD) will be submitted to the NIMH Data Archive within 12 months after completion of the trial according to the NDA submission schedule and policies.

There is no plan to restrict access to anonymized data for research purposes. However, access will be provided through the NDA Data Access Committee (DAC). Investigators and institutions seeking data from NDA will be expected to meet data security measures and will be asked to submit a Data Use Certification.

It is not possible to mask collection of implementation outcomes at the facility level or to blind the primary health center staff to arm allocation.

For patient-level outcomes, outcome assessors and investigators will be masked. Patients who enroll in the study will not be informed about the allocation of their respective facility; therefore, it is unlikely that they would become aware of arm allocation. The study outcome assessors will be blinded to arm allocation of the participants' facilities, and the patient outcome assessments will be conducted at the patient's home or a mutually agreed location, other than the facility. The study team will also ensure separation between the Support Coaching Team delivering the Enhanced Implementation Support strategy and the outcome assessors to avoid any communication that could indicate the arm allocation of participants and facilities.

The statistician who will analyze the final outcome data will also be blinded to arm allocation.