Foster youth, of whom there are over 350,000 across the United States [1], experience high rates of behavioral health (mental health and substance use) needs, yet simultaneously face numerous barriers to accessing and engaging in community-based behavioral health care [2,3]. Compared to their same-age peers, foster youth exhibit higher rates of psychiatric disorders (eg, major depressive disorder and posttraumatic stress disorder), suicidality (eg, ideation and attempt) [4], and substance use and are more likely to initiate substance use at earlier ages [5]. Data also suggest that among foster youth 11‐14 years old who had clinically elevated mental health concerns, only 26% used services [6]. These gaps in access often continue through transition age years (16‐24 years), with youth reporting ongoing barriers to care such as mistrust of the system and transportation challenges [7].

These observed inequities in behavioral health needs and services access are not a result of individual deficits, but rather, a product of complex social and systemic issues, such as poverty and structural racism, that disproportionately impact minoritized groups [8], including foster youth. Of note, families racialized as Black, Indigenous, and Latine are consistently overrepresented in the child welfare system [9,10], with Black youth in particular being more likely to be removed from their homes [11,12].

A growing body of literature has associated behavioral health needs with social determinants of health (SDoH), the social conditions into which a youth is born and grows [13]. Foster youth, who are disproportionately from minoritized ethnic and racial groups, are disadvantaged by multiple SDoH, for example, early childhood exposure to violence, child maltreatment [14], and unstable housing as a result of placement transitions. They are also less likely to access higher education and complete high school [15,16], more likely to experience economic hardship, and less likely to access needed services compared to nonfoster youth peers [6]. Thus, developing accessible supports for foster youth to address unmet behavioral health needs and reduce the undue burden of SDoH is essential. Ensuring these supports acknowledge root cause issues (eg, structural racism) is equally important to securing lasting social change [17].

Common barriers to accessing and engaging in evidence-based interventions among foster youth include frequent relocations due to multiple placement transitions, complex and multifaceted treatment needs, and services that are not designed with their unique experiences in mind [18-21]. Technology-based interventions are promising for overcoming some of these barriers, particularly when designed in collaboration with the intended users (ie, foster youth). The present study describes lessons learned from co-designing a technology-based intervention with and for foster youth to address SDoH and behavioral health needs. While terms like “users” and “end users” are commonly reported in the field to refer to those engaging in the co-design process, we chose instead to center terms such as “youth” and “foster youth” to communicate that these young people are respected and valued regardless of their relationship to the technology in development.

Developing, testing, and implementing technology-based strategies to address documented barriers to care is critical in the journey toward an equitable behavioral health system where foster youth can access the support they desire and need. Technology has increasingly been leveraged to address inequities among minoritized racial and ethnic groups [22,23] and to deliver interventions to foster youth and their families [24,25]. Behavioral intervention technologies (BITs; “websites, software, mobile apps, and sensors designed to help users address or change behaviors, cognitions, and emotional states”; [26]) have the potential to support foster youth in directly accessing resources to address SDoH and behavioral health needs [27]. Mental health apps—one type of BIT—have proliferated, with estimates suggesting over 20,000 exist for download [28]. BITs for youth can promote easy access to behavioral health care by providing intervention at any time and allowing for personalization [29,30].

However, simple repackaging of evidence-based interventions for digital use may be insufficient to address existing inequities. Research has shown that despite an influx in the number of BITs developed, engagement with these technologies continues to be low [31]. Participatory methods that engage youth from the start of BIT development have been proposed as one potential solution to increase engagement [32,33]. Of the existing mental health apps for young people, however, only 30 have published descriptions of being co-designed with the youth they intend to serve, and only 3 were co-designed specifically with minoritized youth communities (eg, indigenous youth, lesbian, gay, and bisexual youth) [32]; this paucity of literature suggests significant room for the field to improve in its use of participatory co-design approaches with youth.

Co-design approaches to developing BITs are intended to center youth involvement through a range of user-centered design principles, such as creative collaboration, iterative design, and acknowledgment of power differentials [32,34]. Recentering minoritized communities through such processes is also one of many necessary steps toward countering structural oppression within existing systems of care [35,36]. But the term “co-design” has been used in the literature to reference a continuum of involvement, ranging from brief consultation to more intensive, integrated involvement through mutual partnership. Greater specificity is needed to understand the utility and application of co-design approaches [32,33] and to avoid the potential of harm being perpetuated through the use of these very methods when not applied thoughtfully [37].

Participatory informatics is one approach to the co-design of BITs [38-40]. Drawing on principles of community-partnered participatory research (eg, equity and power sharing) and user-centered design (eg, active user participation in design), participatory informatics involves including people from the population you intend to serve as equitable members throughout the design process [38,39]. This approach does not require the youth to have technological expertise and instead places value on their lived expertise. Participatory informatics is therefore able to address community priorities through tools that are engaging and relevant, while also increasing co-designers’ own perceived competency in creating BITs, fostering a culture of co-leadership related to the work, and promoting sustained engagement with BITs; additional information on how we applied this to our co-design process is outlined below. Participatory informatics has been used in studies with ethnically and racially minoritized communities to address a wide range of health needs [38,41,42] and within a variety of health care settings [41,43]. To our knowledge, this approach has yet to be applied with foster youth.

Participatory co-design of BITs with minoritized young people, such as foster youth, requires thoughtful attention to power dynamics, varying levels of technology access and literacy, and a range of SDoH needs, among other considerations. To support other scholars interested in co-designing BITs with minoritized youth to address SDoH and increase access to and engagement in behavioral health care, the current paper presents lessons learned from a 31-month participatory co-design process of a BIT (“FostrSpace”; Chorus Innovations, Inc) created by and for foster youth in California. We define the app development process (co-design and its benefits), provide a detailed description of the FostrSpace platform, and summarize lessons learned. A focus is placed on how participatory co-design was used in order to center the voices of foster youth, allowing them to speak to their needs and the impact of health inequities. For example, youth co-designers described domains of resources and needs they wanted represented within the FostrSpace app; the research team then presented the SDoH framework as a way to organize the app (ie, app features and content were organized around major areas of SDoH, including health care access and quality, educational access, and economic stability). App usage data, collected as part of quality improvement efforts, is used to understand the behavioral health and resource needs of users. This work builds upon our prior examinations of co-designers’ reflections on the participatory co-design process [44] and initial usage data for FostrSpace in an ongoing hybrid implementation-effectiveness trial in partnership with Court Appointed Special Advocate (CASA) programs [45]. Through this description of our methodological application of co-design with foster youth, we aim to provide relevant insights for other scholars and ultimately to encourage the use of such methods to advance behavioral health equity for minoritized youth.

Co-design of FostrSpace began in the planning stages. Idea-sharing workgroups, advertised using digital recruitment flyers distributed by Bay Area organizations serving foster youth, were held with 5 present and former foster youth (ages 16‐26 years); two 90-minute groups were held, one with 3 participants and the other with 2. Workgroup participants were compensated with a US $75 gift card and invited to join the FostrSpace Advisory Board (FAB). FAB members (4 of the 5 workgroup members) were hired as university employees and paid an hourly rate (based on their individual compensation package, which was determined by education level and experience as set by the university) for participation in the co-design process. The FAB consisted of 4 transition-age youth; their personal background and experience co-designing the initial version of FostrSpace have been described elsewhere [44]. For 18 months, the FAB participated in weekly 90‐ to 120-minute meetings with a team of academic clinical researchers (academic team) and developers at Chorus Innovations, Inc, a Health Insurance Portability and Accountability Act (HIPAA)–compliant web-based app development platform.

The process of creating FostrSpace included 5 phases (see Figure 1): design, development, launch, testing and evaluation, and iterative refinement. In the design phase, meetings focused on gathering feedback from the FAB about the app interface, framework, features, and functionality. During these meetings, the FAB team created the app name and theme and identified the primary features of the app. These app features organically fit within an SDoH framework, which addresses key areas of social impact that influence youth behavioral health outcomes (eg, health care access and quality, education access and quality, social and community context, economic stability, and neighborhood and built environment). Co-designers engaged in shared decision-making about FostrSpace features and design, prioritizing the FAB preferences at all stages and taking into account what was possible to create within the existing platform and resources. In the development phase, the Chorus team built the initial version of FostrSpace, the FAB created psychoeducational and testimonial app content, and the care team (ie, behavioral health providers and personal care navigators hired to provide in-app services) developed clinical workflows and triage processes. All content was tested extensively by the FAB and academic team and iteratively refined to improve usability. The launch phase focused on dissemination and outreach to enroll youth to test the app. In the testing and evaluation phase, the team engaged in ongoing strategic testing and quality assurance initiatives to ensure the app was effective, efficient, and user-friendly. Qualitative feedback from youth, including the FAB, informed changes to the app in the iterative refinement phase. The “FAB Chat,” which offers daily in-app peer support from our FAB team to cultivate community, was added during this phase in response to youth feedback. Youth also requested content focused on SDoH relevant to the transition to adulthood, which inspired the FAB to create the “Adulting 101” content and video series, including independent living resources (eg, how to apply to a job or food benefits). Finally, also during the iterative refinement phase, the FostrSpace app and academic team were awarded a federal Children and Youth Resilience Challenge grant, which spanned from September 2023 to May 2024. Through this challenge, our team added 2 new FAB members with lived experience in the foster care system (2 existing members became inactive at this time due to competing personal demands) and added a measure of youth resilience into the FostrSpace app. The FAB worked, on average, 4 hours each week during this time to create new app content, test and refine existing content and features, and engage in outreach activities.

FAB members had a range of experiences in both the traditional foster care system and kinship/relative care and represented a diverse set of backgrounds across race, ethnicity, sexual orientation, gender, disability status, and socioeconomic status (eg, White, White-passing, mixed Asian-Hispanic, Mexican-Latino, and Chicana; nonbinary, woman, and men).

Combining “Foster” and “‘Space,” the name FostrSpace was selected in partnership with the FAB to easily identify the app as a welcoming space for foster youth. The app uses imagery such as astronauts, planets, stars, and rocket fuel to create a lively and developmentally appropriate virtual space for users to explore their mental wellness.

FostrSpace provides access to a wide range of both self-guided and service-oriented features (eg, navigation and clinical services). Self-guided features include psychoeducational content (eg, breathing exercises and regulation skills) and a curated resource directory organized by SDoH area (eg, school and applying to college, employment and training, health care; see Figure 2, Find Resources screenshot) across several SDoH domains (eg, educational, occupational, health care, and legal). Self-guided assessments for emotional wellness and resource needs are incorporated to personalize app content for foster youth and inform the care team of the youth’s self-identified priority needs. Synchronous service-oriented features include chat-based support from peers with lived experience in the foster care system, resource linkage support from a personal care navigator, and behavioral health services via telehealth, which are available weekdays except on holidays from 9 AM to 6 PM (see Table 1).

Foster youth can engage with the app independently or with support from their care team, with features designed to build self-awareness (eg, mood tracking) and promote autonomy (eg, missions). For example, youth have the option to complete a single-item mood check-in question upon each login on the landing page of the app (see Figure 2, Quick Check-In screenshot), with the option to briefly describe their mood in a write-in section; responses are logged over time so youth can revisit them for personal tracking. Youth can also set and track goals (eg, completion of app tutorials and submission of job applications) through “Missions” (see Figure 2, Pick Up Groceries screenshot). When missions are self-generated, foster youth are prompted to add a description of their goal, a timeline on intended goal completion, and log any relevant hyperlinks they might need to complete the task (eg, job application site in the case of a vocational goal). If youth engage in services, goals can also be assigned by the care team to facilitate completion of app-based content, therapy goals, or in-app assessments. Peer support with mood tracking and goal organization is accessible through in-app chat with the FAB.

Youth seeking emotional wellness resources are invited to complete the in-app Emotional Wellness Questionnaire (EWQ; a co-designed behavioral health assessment including items from the DSM-5 [Diagnostic and Statistical Manual of Disorders {Fifth Edition}], Self-Rated Level 1 Cross-Cutting Symptom for adults [18+ years] and youth [11-17 years] measuring frequency and severity of past 2-week symptoms [41]). All respondents receive feedback on their responses (see Figure 2, Emotional Wellness Quiz screenshot with astronaut and rocket fuel metaphor for emotional wellness, ie, behavioral health intervention need) and tailored resources (eg, self-guided psychoeducational content to learn coping skills), and for those whose responses are elevated, the suggestion to connect with a FostrSpace clinician. FostrSpace navigators send an in-app chat message within 48 business hours to youth with elevated scores to offer support with connecting to a FostrSpace clinician. Foster youth may also opt to message the navigator directly to request help initiating clinical services. Navigators serve as the primary point of contact, supporting youth in accessing appropriate mental health resources. For youth not yet ready to engage with a mental health clinician (whether through FostrSpace or external services), navigators address barriers to care and co-develop a gradual, youth-paced plan to facilitate connection to desired resources. Foster youth who engage with FostrSpace clinicians are asked to complete follow-up questionnaires (ie, DSM Level 2 Cross-Cutting Symptom Measures; [46]) to inform clinical intervention needs in particular area(s) (eg, depression, anxiety, substance use). All FostrSpace clinicians are trained and experienced in providing care to youth with current or prior history of foster care system contact.

Outreach efforts included contacting 220 individuals across 153 schools through the Guardian Scholars Program (designed to support foster youth in higher education), 1805 school personnel across 58 counties through the California Department of Education Services, and 42 community-based organizations; in total, we outreached to 2300 contacts (from September 1, 2021, to April 13, 2024). In addition to cold emails and direct contact with community organizations that serve foster youth, our team presented at 5 state-level child welfare leadership meetings and hosted 8 virtual events for the statewide foster youth community directly, where training in policy and advocacy was provided and access to the app was highlighted. As described below, despite this extensive outreach, enrollment during the evaluation period was lower than anticipated (n=40).

Data reported in the current manuscript were collected between April 25, 2022, and November 14, 2024 in-app and used solely for quality improvement purposes to improve FostrSpace over time. An in-app data use agreement was signed by each youth as part of the FostrSpace sign-up process. Youth were provided with the following statement: “The data collected will be used to maintain the FostrSpace app’s functionality and performance and support FostrSpace service provisions. Information collected through FostrSpace could include your name, contact information, responses to surveys, and/or engagement activity (log-ins, completion of surveys). Information about who has access to your data and where it is stored can be accessed within the app under the “My Data” section. At any time, you can request to be removed from the platform and have your data deleted.” All data were stored within the FostrSpace app on the Chorus platform and used only for internal quality improvement purposes. Data sent to or from the FostrSpace app is transmitted over encrypted, industry-standard connections like SSL/TLS. The server is protected using standard practices, including being located behind a network firewall and accessible only by designated users. No data are stored locally on users’ devices (such as local browser storage or temporary storage) that access FostrSpace. App usage data were analyzed using descriptive statistics to understand the behavioral health and resource needs of users.

The institutional review board of the University of California, San Francisco, determined that this research is exempt from institutional review board oversight according to the federal regulations summarized in Title 45 of the Code of Federal Regulations, Part 46.102(l). Demographic information was intentionally not collected from app users except for age, which was needed to determine eligibility. This decision was driven by our desire to ensure the app remained accessible and safe for a population of young people who are highly surveilled. Demographic information was collected for those engaging in services; however, given the small sample size, we do not include this information here.

The current manuscript describes lessons learned from the process of creating FostrSpace, a BIT designed for and by foster youth. Considerations for interpreting our recommendations include that the work was conducted in a single United States state with a small FAB, which could impact generalizability; we used a web-based app platform, and challenges and opportunities may differ for other platforms such as native apps; and we did not conduct a formal evaluation of the app during the initial testing stages, but rather report available quality improvement data.

Lessons learned from the process of creating FostrSpace can inform researchers seeking to co-design BITs with foster youth, as well as young people more broadly. There is no one-size-fits-all approach to engaging in co-design, and as such, we encourage researchers to provide greater specificity regarding the co-design methods used so we can advance our scientific understanding of how best to engage in this type of work. Relevant across co-design methodologies, our experience highlights the importance of active reflection throughout the process to ensure the creation of a psychologically safe and constructive co-design space where young people, academics, and developers can work together to create accessible and impactful BITs. One element of this is ensuring adequate resource investment before beginning the process (eg, available compensation for co-designers and time commitment of all involved) to avoid replicating harmful research practices of extracting from minoritized communities, as co-designing BITs can take significant time and resources. This time-intensive participatory approach can run counter to deadlines and expectations set by institutions and funders [47], and broader advocacy for the centrality of these methods to advancing health equity is needed to ensure their feasibility within existing structures.