Introduction

Approximately one in every 6 children and adolescents in the USA (US) has a diagnosable mental health condition (Whitney & Peterson, 2019). Rates of youth mental disorders have been steadily worsening over the past decade, and today the need for mental health treatment greatly exceeds the capacity of the mental health care system. As a result, only a fraction of affected youth receives mental health services (Ghandour et al., 2019; Whitney & Peterson, 2019). The unmet need is highest among minoritized youth, youth from lower socioeconomic backgrounds, and youth residing in rural areas (Hoffmann et al., 2022; Rodgers et al., 2022). The COVID-19 pandemic further exacerbated these long-standing trends (COVID-19 Mental Disorders Collaborators, 2021; Racine et al., 2021), leading multiple professional organizations to declare a national emergency in child and adolescent mental health (American Academy of Pediatrics, 2021) and the Office of the US Surgeon General to issue an advisory statement on youth mental health (US Department of Health and Human Services, Office of the Surgeon General, 2021).

In 2022, the federal government responded to these growing concerns by investing one billion dollars over five years to support school-based initiatives focused on youth mental health, including initiatives designed to expand the school mental health workforce and to increase access to evidence-based and culturally relevant mental health services (The White House, 2022). This includes funding for Health Resources and Services Administration (HRSA) grants to expand school-based health services and centers, as well as additional funding for the Substance Abuse and Mental Health Services Administration’s (SAMHSA) Project AWARE (Advancing Wellness and Resiliency in Education) block grant program to support the development of a sustainable infrastructure for school-based mental health programs and services (US Department of Health & Human Services, 2022a, b; US Department of Health and Human Services, Substance Abuse and Mental Health Services Administration, 2023c). In early 2024, the Centers for Medicare & Medicaid Services announced an additional 50 million dollars in planning grants to support the development, implementation, and expansion of school-based health services, with a concentration on mental health services (Centers for Medicare & Medicaid Services, 2024). Taken together, these federal investments demonstrate a clear interest in leveraging schools to mitigate the youth mental health crisis.

The National Institute of Mental Health (NIMH) recently issued a Notice of Special Interest, NOT-MH-24-165: School Mental Health: Innovative Approaches to Expand Access to Evidence-Based Interventions and Services (US Department of Health & Human Services, 2024), to encourage school mental health research. Aligned with Objectives 3.2 and 3.3 and 4.1 and 4.3 of the NIMH Strategic Plan for Research (US Department of Health and Human Services, National Institutes of Health, 2023b), this NOSI encourages studies that address questions related to the effectiveness, implementation, and scaling of evidence-based practices and services in school and afterschool program settings. In accordance with the NIMH Strategic Framework for Addressing Youth Mental Health Disparities (US Department of Health and Human Services, National Institutes of Health, 2023a), the NOSI also prioritizes research that seeks to reduce disparities in outcomes for racial and ethnic minority groups, individuals limited by language or cultural barriers, sexual and gender minorities, individuals living in rural areas, socioeconomically disadvantaged persons, and other underserved groups.

The Promise and Challenges of School-Based Mental Health Interventions

Schools serve as a critical setting for connecting and providing youth with preventive and therapeutic mental health interventions (Locke et al., 2017; Panchal et al., 2022). With an estimated 49 million youth attending a public primary or secondary school in the US (National Center for Education Statistics, 2024), there is great potential within school systems for identifying youth in need of mental health support and connecting them with appropriate interventions. Studies have indeed shown that youth are more likely to receive mental health interventions when they are provided at school, and they have greater levels of adherence and engagement with these interventions when compared to youth who receive prevention and treatment in other settings (Evans et al., 2023; Langer et al., 2015; Sanchez et al., 2018).

While many studies have demonstrated both the feasibility and effectiveness of school mental health interventions for improving or preventing youth mental health symptoms and enhancing academic outcomes (Evans et al., 2023; Hoover & Bostic, 2021; Lai et al., 2016; Richter et al., 2022; Ross et al., 2020; Sanchez et al., 2018), findings have not been universally positive. These mixed results reflect some of the challenges associated with delivering mental health interventions and services in school settings. Logistical challenges include budget limitations, high rates of staff turnover and staffing shortages, scheduling constraints, and limited time in the school day for activities that are not clearly academic. Social barriers also exist, including stigma, a lack of awareness of mental health issues, and difficulty engaging parents and obtaining parent consent for student interventions. Lastly, factors related to school climate, the integration of community partners into the school setting, the limited availability of culturally sensitive evidence supported interventions, and policy and structural factors all contribute to intervention effectiveness (Cummings et al., 2023; Eiraldi et al., 2015; Frank et al., 2022; Langley et al., 2010; Richter et al., 2022; Splett et al., 2022).

NIMH Priorities and Opportunities for Developing Optimized School-Based Interventions

Despite the potential for schools to expand access to evidence-based mental health services, the above challenges have contributed to the limited uptake and sustainment of evidence-based mental health interventions (Cook et al., 2019; Owens et al., 2014). NIMH priorities in school-based mental health research are focused broadly on addressing these challenges through the iterative development and testing of optimized, scalable, and culturally responsive school-based interventions. Specific examples of school-based intervention research priorities include: optimizing and testing research-supported interventions and services that can be readily deployed in school settings using available resources and personnel; refining and testing strategies for implementing interventions with fidelity by personnel in school settings; evaluating tiered approaches that can be used for prevention through treatment, including stepped-care approaches that may identify students for specialty mental health care; adapting and optimizing existing evidence-based interventions and services to substantially improve treatment response, care, and/or uptake for diverse students and families; and refining and testing the utility of low burden measurement-based care tools to inform and enhance interventions and services in school settings (US Department of Health & Human Services, 2024).

Across all of the above priority areas, and consistent with NIMH Strategic Objective 3 of the NIMH Strategic Plan for Research (US Department of Health and Human Services, National Institutes of Health, 2023b), NIMH strongly encourages collaborations with school and community partners early in the research planning process and their ongoing involvement throughout the iterative intervention development and testing process. A deployment-focused approach that includes school and community partner perspectives from the outset helps to ensure that the resultant intervention can feasibly be implemented within the school context using existing school and community resources (Weisz, 2014). In addition, NIMH encourages research approaches that maximize efficiencies by utilizing existing infrastructure to facilitate data collection, improve the feasibility of identifying students appropriate for the experimental intervention, and enhance the sustainability of the approach. Resources developed and supported through block grant programs like SAMHSA’s Project AWARE, which provides school districts with funding to build mental health service capacity and develop collaborative partnerships that support the delivery of mental health interventions, represent one example of sustainable infrastructure. Additional examples include utilizing existing school administrative data and data collection methods to identify students and match them to appropriate interventions, embedding interventions into existing school-based health centers and using center providers to deliver the intervention, and using existing professional development models to facilitate teacher training in evidence supported classroom-based interventions.

NIMH funds school-based intervention research through a suite of clinical trial Notices of Funding Opportunity (NOFOs). These include a pilot clinical trial NOFO for the development of optimized interventions (PAR-21-131; US Department of Health and Human Services, National Institutes of Health, 2021b) and a NOFO that supports well-powered studies of optimized interventions that have already undergone pilot testing (PAR-21-130; Department of Health and Human Services, National Institutes of Health, 2021a). NIMH encourages intervention development research when there is a compelling empirical justification for the proposed modification or augmentation. This justification may be based on evidence that the unadapted intervention is associated with suboptimal engagement, adherence, or clinical response, is a poor cultural fit for specific populations, or is likely to encounter implementation challenges in school settings (National Advisory Mental Health Council Workgroup, 2010).

The intervention development research funded through the pilot effectiveness NOFO (PAR-21-131) may emphasize intervention refinement, personalization, optimization, augmentation, or sequencing to enhance the clinical impact or cultural fit of the intervention, and/or to improve the feasibility of implementation in school settings. Across all research topic areas, NIMH encourages an iterative intervention development and testing process that spans a series of three steps. Step 1: systematically evaluate of the characteristics of typical intervention consumers, providers, and the intended delivery setting and obtain feedback from community and practice partners. Step 2: operationalize and develop the experimental intervention or implementation strategy and iteratively refine the approach within the context of a case series or similar methodology (e.g., to establish dosing, refine intervention manuals and training materials). Step 3: conduct a pilot hybrid trial to generate preliminary outcome and implementation data as a prerequisite to a fully powered hybrid trial. Pilot research funded through the pilot effectiveness NOFO (PAR-21-131) must include Step 3 at a minimum and may also include Steps 1–2 as appropriate.

All NIMH clinical trial NOFOs that support school-based intervention research encourage the use of hybrid effectiveness-implementation trial designs (Curran et al., 2012). Hybrid trials seek to simultaneously evaluate the clinical impact of the intervention on symptoms, functional outcomes, or risk factors associated with a mental disorder as well as implementation factors or strategies that impact the delivery of the intervention in the intended setting. Consistent with the NIMH experimental therapeutics approach to clinical trials (Gordon, 2017), these NOFOs also require that study designs include an examination of at least one hypothesized mechanism of action, or target mechanism. NIMH defines a mechanism of action as a factor that an intervention intends to modify based on a hypothesis suggesting that modification will result in improved mental disorder risk, symptoms, or functional outcomes. The exact nature of the mechanism will vary based on the intervention characteristics. In school-based intervention research, mechanisms typically include specific student psychological, behavioral, or interpersonal processes, intervention skill use, or teacher adherence to a classroom-based intervention. Importantly, the proposed mechanism of action should be a construct that can be measured feasibly in school contexts using valid measures that are widely accepted by the field. NIMH also supports non-clinical trial research that aims to develop and evaluate performance feedback systems, decision support tools, and quality improvement projects that optimize the delivery of effective mental health interventions in schools and other non-specialty care settings (PAR-22-082, PAR-21-316; US Department of Health and Human Services, National Institutes of Health, 2021c, 2022b).

In summary, optimized school-based mental health interventions and implementation strategies have the potential to address the vast unmet need for effective and accessible youth mental health prevention, early intervention, and treatment services. While recent federal investments will provide schools with support to expand access to mental health interventions, additional research is needed to ensure that culturally appropriate, evidence-based interventions are available and have been optimized for implementation in school settings. Strong partnerships between academic researchers and school communities are needed to generate optimized interventions that bridge the research-to-practice gap and enhance the uptake and sustainability of evidence-based approaches in school settings. Studies that capitalize on existing practice infrastructures for school-based services can accelerate the translation of research findings into practice and allow researchers to efficiently address NIMH school research priorities. Collectively, such studies will yield an enhanced empirical foundation of mental health research that can help schools reach their potential as sustained providers of accessible, culturally appropriate evidence-based interventions for youth across the USA.