Trauma-Informed Care as a Promising Avenue for Supporting the Transition to Adulthood Among Trauma-Exposed Youth: A Scoping Review

1. Introduction

Adverse childhood experiences (ACEs), such as abuse, neglect, household dysfunction, poverty, and exposure to community violence or peer victimization, are undoubtedly common [1]. A meta-analysis from Madigan et al. [2] revealed that 66% of adults report they have had ACEs, and rates are even higher among child welfare or foster care samples [3,4]. Cyr et al. [4] found that 90% of children and youth in a child welfare sample disclosed at least one form of victimization and that 54% reported polyvictimization in the past year. Similarly, Collin-Vézina et al. [3] showed that half of youth in a foster care sample revealed that they had experienced four or more forms of maltreatment, as well as clinical levels of depression, anger, post-traumatic stress, and dissociation. Children and youth in child welfare or foster care may also experience system-induced trauma from being separated from family, friends and community; placement instability; or violence [5,6,7]. Thus, a proportion of children and youth, especially those in the child welfare or foster care systems, have histories of cumulative childhood trauma.

Childhood trauma is associated with mental health issues, social-emotional difficulties, cognitive and language problems, educational challenges, as well as difficulties related to identity and self-esteem throughout development, including during the transition to adulthood (TA) [8,9,10,11,12,13]. The TA is a developmental period characterized by change, exploration and challenges in multiple interrelated aspects of development and functioning, when the ultimate goal is to achieve autonomy [14,15,16]. Trauma has a documented impact on development, which may also affect functioning and well-being in transition-age youth (TAY) [13,17,18,19,20,21]. Involvement in the child welfare or the foster care systems could impact the TA because of the reduction or cessation of services combined with the lack of social support from family, friends, and community that is documented among youth exiting those systems (i.e., aging out of care) [22].

1.1. TA Outcomes Among Trauma-Exposed Youth

Studies indicate that trauma-exposed TAY – including those in the child welfare or foster care systems – have poor outcomes in multiple aspects of functioning, including education and employment, economic and living situation, and mental health and social functioning [18,19,20,23,24]. For example, youth with child welfare involvement are found to have poorer educational outcomes than youth from the general population [20] or youth from low-income backgrounds [25]. A study of over 63,000 high school students revealed that youth with child welfare involvement had lower rates of high school completion and college enrollment, poorer educational performance, and greater academic challenges (i.e., special education–qualifying disabilities, school district changes, underperforming school districts) than youth from low-income backgrounds with no child welfare involvement [25]. A review showed that 38% to 83% of former foster youth have a high school diploma, 28% to 56% enroll in post-secondary education, and 17% to 49% are not in education, employment, or training [20]. Notably, when these youth are employed, the jobs are likely to be less stable with lower pay and to require low qualifications [18,20,23]. Thus, trauma-exposed youth show overall poor educational and employment outcomes.

Economic hardship and stress due to educational or employment challenges may in turn impact living situation and mental health, and conversely, homelessness, housing instability and mental health problems may cause additional educational and employment challenges [23]. Not having a high school diploma, having low educational attainment, and being unemployed have been found to be critical risk factors for homelessness, housing instability, and mental health issues [18,23,26]. A prospective longitudinal study of more than 2,500 foster youth showed that one-third experienced at least one episode of homelessness and that one-fifth experienced housing instability at age 21 [27]. This study also showed that 32% (age 17) and 39% (age 19) of them reported mental health issues, including depression, anxiety, attention deficit hyperactivity disorder symptoms, or suicidal behaviors [28].

In sum, trauma-exposed youth and, to a greater extent, youth with involvement in the child welfare or foster care systems are at risk of poor TA outcomes in terms of multiple interrelated aspects of development and functioning [29], hence the need to explore initiatives aimed at supporting the TA of these youth.

1.2. Services and Programs Aiming to Support the TA

A systematic review of eight studies on the effects of services and programs aiming to support the TA yielded mixed results [30], while a meta-analysis of eight studies showed that they had significant but small effects on outcomes related to education, employment, and living situations [31]. Program differences and methodological limitations somewhat precluded comparisons and the drawing of conclusions about the effects of the services and programs studied in this review and meta-analysis [30,31,32]. The most present and empirically supported initiatives include services and programs providing youth support past the age of majority [17,20,23,30,33,34,35]. However, they are not consistently available in the child welfare or the foster care systems [20,30,31,33], and it is agreed that services should aim to prepare youth to TA early, well before they reach the age of majority or exit the child welfare or foster care systems [20]. Thus, existing services or programs – when available – may not be sufficient to fully support TA outcomes among youth with histories of trauma, highlighting the need to explore complementary approaches, such as trauma-informed care, to enhance services [17].

One limitation of the programs and services reviewed is that they do not formally or specifically acknowledge and respond to trauma and its impact. Given that childhood and system-induced trauma may impact functioning and well-being during the TA, services and programs aiming to support education and employment, economic and living situation, or mental health and social functioning in TAY should address trauma [17,18,19,20]. Trauma-informed care (TIC) is a promising approach that may address this limitation.

1.3. Trauma-Informed Care

TIC involves systemic changes in both organizational policies and clinical practices to “realize the widespread impact of trauma and understand potential paths for recovery; recognize the signs and symptoms of trauma in clients, families, staff, and others involved with the system; and respond by fully integrating knowledge about trauma into policies, procedures, and practices, and seek to actively resist re-traumatization” [5] (p. 9). While inclusive of trauma-focused interventions emphasizing the assessment and treatment of trauma symptoms, TIC integrates six principles (safety; trustworthiness and transparency, peer support; collaboration and mutuality; empowerment; and cultural, historical, and gender issues) into policies, procedures, and practices to respond to the needs of individuals with histories of trauma [5]. As such, by acknowledging and responding to trauma and its impact (e.g., mental health issues, socio-emotional difficulties, cognitive and language problems, and difficulties related to identity and self-esteem), a trauma-informed lens creates the opportunity to understand and respond to the needs of youth to support them in multiple aspects of development and functioning, and in turn, improve their education and employment, economic and living situation, and mental health and social functioning outcomes during the TA. As such, TIC is believed to be a promising avenue for supporting the TA [20].

A meta-analysis showed TIC interventions have significant and moderate effects on trauma symptoms, behaviors, and well-being in children and youth [36] . Several studies on trauma-exposed TAY recommend TIC [e.g., [21,37,38,39]], and the Child Welfare League of Canada [35] affirms that foster youth must have the right to receive TIC interventions. The Child Welfare League of Canada also identified eight pillars that support the TA of foster youth. The pillars (education, employment, basic needs, social support and relationships, conduct and victimization, health and well-being, general living skills, and resilience and psychological empowerment) align with TIC principles and are corroborated in the literature as targets for supporting the TA [5,32,40]. While there is growing recognition and implementation of TIC across child welfare and foster care systems [41], most initiatives do not specifically aim to support the TA, although some programs or services are available. A preliminary search of databases was conducted, and no ongoing or available review of such initiatives was identified. This scoping review was therefore undertaken to fill this gap in knowledge and explore the extent of the literature on the potential of TIC to support the TA of trauma-exposed youth. The research questions were as follows:

• What are the existing needs and TIC approaches to specifically support the TA of trauma-exposed youth?
• What are the effects of implementing TIC approaches?

2. Materials and Methods

This scoping review was conducted following the JBI methodology for scoping reviews [42], as well as the PRISMA extension for scoping reviews [43].

2.1. Eligibility Criteria

2.1.1. Participants

The review focused on TAY with histories of trauma. The review adopted an inclusive approach and targeted all youth with child welfare or foster care involvement, or with histories of ACEs or interpersonal traumatic events. Although youth aging out of the child welfare or foster care systems may face additional challenges [22], experiencing childhood trauma in itself is likely to affect the TA so all youth with histories of trauma could require TA support and therefore were considered [17,21]. Thus, to be included in the review, references had to target youth who have been exposed to ACEs or interpersonal traumatic events (e.g., abuse, neglect, household dysfunction, poverty, peer victimization, peer isolation/rejection, and community violence exposure) or who are or have been involved with the child welfare or foster care systems. Non-interpersonal traumatic events (e.g., natural disasters, traumatic brain injuries) or war were not considered in this review to ensure a degree of homogeneity and because the impacts and mechanisms involved in those cases are somewhat different [44].

The age range for the TA period varies across studies and authors. Arnett [14] identifies emerging adulthood as the late teens to the early twenties (18 to 25 years old), whereas the Spinelli et al. [21] sample of TAY includes those aged 14 to 21 years old. Again, we adopted a more inclusive approach, and, as a general rule, we focused on youth between the ages of 14 and 25 years old. This general age band is in line with the acknowledgement that services should aim to prepare youth for the TA before they reach the age of majority, and that the TA period may exceed the twenties. Participants could be youths or other persons involved with TAY with histories of trauma (e.g., researchers, policy-makers, practitioners, service providers).

2.1.2. Concept

References had to focus on outcomes related to education and employment, economic and living situation, or mental health and functioning during the TA.

2.1.3. Context

References also had to focus on services, programs or initiatives grounded in TIC, whether they highlighted the need for a TIC approach to support the TA, described a TIC approach aimed at supporting the TA or evaluated a TIC approach. We used the Substance Abuse and Mental Health Services Administration’s (SAMHSA) definition of TIC in which TIC involves systemic changes in both organizational policies and clinical practices to “realize the widespread impact of trauma and understand potential paths for recovery; recognize the signs and symptoms of trauma in clients, families, staff, and others involved with the system; and respond by fully integrating knowledge about trauma into policies, procedures, and practices, and seek to actively resist re-traumatization” [5] (p.9). When a reference included an intervention focusing on the assessment and treatment of trauma symptoms (e.g., trauma-focused cognitive-behavioral therapy [TF-CBT]) [45], it was included only if the intervention was part of a wider implementation of TIC aimed at changing organizational policies and clinical practices. Otherwise, it was not included.

2.2. Types of Sources

This scoping review did not limit study design (e.g., observational, cross-sectional, program evaluation) or methods (qualitative, quantitative, mixed, review) to broadly explore the extent of the literature on the topic. Previous reviews that met inclusion criteria were considered, as well as text and opinion papers and other types of references (e.g., websites, conference proceedings, government or organization documents). Only documents in English or French were included, and only one study was excluded because of language [46]. A date limit was not applied because a previous review has not been done on the topic.

2.3. Search Strategy

The goal of the search strategy was to locate both published and unpublished documents and other types of references. A preliminary search of PsycINFO (Ovid) was undertaken to identify articles on the topic. Words in titles and abstracts, keywords, and index terms of the relevant articles identified through this preliminary search were used to develop the search strategy for PsycINFO (Ovid) with the assistance of a university librarian (see supplementary material, Table S1 for the search strategy for PsycINFO). The search strategy was then adapted to eight other databases: Medline (Ovid), ERIC (ProQuest), PTSDpubs (ProQuest), Sociological Abstracts (ProQuest), Social Services Abstracts (ProQuest), Social Sciences Abstracts (EBSCOhost), Social Work Abstracts (EBSCOhost and Ovid), and CINAHL Plus with Full Text (EBSCOhost). The search was first conducted in the summer of 2022 and then updated in July 2023.

The reference list of all included sources of evidence was screened for additional references. A search of relevant sources that cited the included references was also done. Unpublished or gray literature was searched using keywords in Analysis & Policy observatory, Information for practice news, new scholarship & more from around the world, OpenAIRE, Publications of the Government of Canada, Policy Commons, Intergovernmental Organization Search Engine – Google, Non-governmental Organization Search Engine – Google, Bielefeld Academic Search Engine, and Google Scholar.

2.4. Sources of Evidence Selection

All references were uploaded into Covidence, a platform that streamlines evidence synthesis with a gold standard process [47]. Duplicates were removed. Titles and abstracts were screened in duplicate by three independent reviewers using the eligibility criteria. The reviewers were two social sciences undergraduates and one graduate student working closely with the principal investigator who specializes in trauma and TIC. The full texts of relevant references were then retrieved and imported into Covidence. Similarly, the full texts were assessed in duplicate by two of the three independent reviewers. Any disagreements between the reviewers at each stage of the selection process were resolved through discussion with the principal investigator. Reasons for exclusion were recorded at each stage. The results of the search and the selection process are reported in a flow diagram (see Figure 1) in the Results section. The search yielded 4320 references (2748 duplicates removed), from which a total of 19 were included. The inter-rater reliability indices indicated quasi-substantial agreement for title and abstract screening (ĸ = .59) and full-text assessment (ĸ = .56) [48].

2.5. Data Extraction

Data were extracted by two reviewers using a tool adapted from the tool provided by Covidence (supplementary material, Table S2). It was adjusted to suit the objective and research questions. The draft adapted tool was pre-tested and then revised to allow information about the following to be extracted: context of the work (e.g., country, type of document, aim), methods (e.g., data collection, sample description, outcome measurement), definitions of main concepts (TIC, ACEs/trauma, TA), analyses, results, limitations, and the TIC services, programs or initiatives. Data extraction was verified by the principal investigator.

2.6. Data Analysis and Presentation

References were classified into three categories based on aim and content: (1) need for or importance of a TIC approach to support the TA; (2) description of a TIC approach aimed at supporting the TA; (3) or the evaluation of a TIC initiative. These categories reflect the usual sequence of program development, implementation and evaluation.

3. Results

3.1. Description of Included References

A total of 19 references were included in this scoping review (see Figure 1). About a third were peer-reviewed articles (k=6), while most were gray literature, including reports (k=4), dissertations (k=3), government or organization documents (k=3), conference proceedings (k=2), and a book chapter (k=1). Most of the work was carried out in the United States (k=12), while the rest originated from Canada (k=3), Australia (k=2), the United Kingdom (k=1) or were international (k=1). The earliest reference dates from 2012, while the most recent is from 2021. As stated above, references included were classified into three categories: (1) need for or importance of a TIC approach to support the TA (k=5); description of TIC practices and policies aimed at supporting the TA (k=5); (3) the evaluation of a TIC initiative (k=2); with some references classified into more than one category (k=7). Table 1 summarizes by category key details about and objectives and methods of included references. Note that information included in Table 1 is based on the information provided in the references, as well as on the category of the document.

3.1.1. Need for or Importance of TIC

References in this category prioritized qualitative (k=4) or mixed methods (k=1) to highlight the importance of or need for a TIC approach to support the TA of youth with histories of trauma. In the qualitative studies [49,50,51,52] youth, service providers and key stakeholders were consulted through photovoice, interviews and focus groups. A last reference in this category was a review [49]. As for the mixed method study [53], an online survey including self-report questionnaires and open-ended questions was administered to service providers working with TAY to assess the providers’ training needs.

3.1.2. Description of Practices and Policies

A total of five references described TIC practices and policies for supporting the TA of youth. While some references presented models or adaptations of models grounded in TIC (Housing First for youth [54]; Therapeutic Family Model of Care [TFMC] [55]; Families Over Coming Under Stress [FOCUS] [56]), others identified trauma-informed principles or guidelines to support the TA of youth [57]. One reference reviewed models that support policy and practice related to youth aging out of care, with some including TIC principles [58].

3.1.3. Evaluation of TIC

One mixed method and one quantitative study assessed the effects of TIC implementation. The mixed method study [59] conducted a three-year evaluation of the LEADS (Learn – Educate – Achieve – Dream – Succeed) program to describe the characteristics and perceptions of the youth served, the types of services provided, the factors associated with success, and the TA outcomes. The quantitative study [60] used census data from the Detroit Jobs for Michigan Graduates (JMG) program to assess youth’s educational and employment achievements at three points (at intake, and during and after the program). JMG comprises three different programs, including LEAP (Learn and Earn to Achieve Potential), which advances a TIC approach.

3.1.4. Importance, Description and Evaluation of TIC

Seven references using qualitative (k=1), mixed (k=3) or other types of methods (k=3), pertained to more than one of the above reference categories. To promote the TA for youth aging out of care, Harder et al. [61] proposed principles grounded in TIC from a qualitative process that considered implications for practice as well as research support. Similarly, a critical review of data and a consultation of stakeholders [62] led to the identification of best practices (which included trauma-informed ones) to support the TA of youth. One mixed method study consulted youth through surveys, interviews, and focus groups to underline the importance of a TIC approach for supporting the TA and to evaluate youth’s experiences and outcomes [63]. Another mixed method study used surveys and focus groups to consult youth and service providers; assess needs, strengths, barriers and strategies while coping with trauma; and document the implementation of a TIC approach and its most effective components [64]. The other mixed method study surveyed and interviewed staff to assess the development and implementation of the Trauma Recovery Model (TRM) [65]. Finally, the study on the LEAP initiative, which involved interviewing youth and reviewing program participation and financial data, described the implementation of the initiative, youth engagement and perspectives, and program costs [66,67].

3.2. Results of Included References

Supplementary material, Table S3 presents the main results from the included references. This section synthesizes results and focuses on findings relevant to the research questions.

3.2.1. Evidence of the Importance of or Need for TIC to Support the TA

Although the included references indicated that services aimed at supporting the TA need to be trauma-informed, Harder et al. [61] highlighted that TIC may not be present enough in services, and that staff need trauma-informed training, support and supervision, which is in line with other accounts [53]. While youth indicated that service providers could benefit from training [64], service providers also communicated training needs related to culture, behavioral and mental health, and youth support and empowerment [53]. Other studies underlined training needs related to trauma, its triggers and its impact [49,64], and to culturally adapted [50], and intersectionally focused services [51]. Butters [62] and Harder et al. [61] highlighted the importance of changes at the organizational and systemic level. Schubert [52] indicated that organizational changes could involve the presence of reference people within organizations to provide information and support through a trauma-informed lens.

The reviewed references highlighted the TA-related needs of youth with histories of trauma and indicated that a TIC approach could be a promising avenue for responding to those needs. The evidence showed that youth could benefit from extended services, collaboration between organizations, a strength-based approach, and support towards education, employment, housing, etc. [49,50,51].

3.2.2. Description of Existing TIC Practices and Policies Supporting the TA

A few services, programs and initiatives grounded in TIC are described in the literature, although they have not been assessed. Those initiatives are reviewed here as they may provide guidance on practices and policies that may support the TA of trauma-exposed youth. Three references aimed to identify principles or recommend best practices [57,61,62]. Butters [62] recommended that practices should be trauma-informed to acknowledge the interrelation between trauma and its impact, and to facilitate recovery [62]. Harder et al. [61] underlined 10 principles for promoting the successful TA of youth aging out of care (e.g., access to education, relationship continuity and safety nets, working through trauma, ensuring access to services). Six supplementary principles were highlighted by Kisiel et al. [57], including understanding trauma and its impact on youth and service providers (secondary traumatic stress).

The review of the Child Protection Project Committee [58] identified at least two models including TIC principles (i.e., The New Zealand’s Oranga Tamariki/Ministry for Children’s policy and The Independent Youth Housing Program). The models adopted were strength-based and described as trauma-informed, youth-centered, holistic and culturally adapted. The Independent Youth Housing Program, an evidence-based program, offers services ranging from rental assistance and case management to helping youth with housing and independence through a trauma-informed lens [58].

Three other models were described [54,55,56]. The first, Housing First for Youth, is used as a philosophy or a guideline by organizations working with homeless TAY [54]. It is based on TIC and aims to support youth with health and well-being by prioritizing awareness and understanding of trauma, and by responding to it at a systemic level (including the organizational structure, the treatment framework, and ongoing training). The second, the TFMC, was developed to assist TAY with histories of trauma with education, employment, development, social relationships and well-being [55]. It focuses on relationships between youth and carers to help youth develop interpersonal relationships and skills. The third, the FOCUS model, is a resilience-based model that assists foster families and youth in college with family functioning and routines, mental health, social skills, and understanding reactions to stress [56]. Thus, the TIC initiatives reviewed in this section, although they have not been assessed, aim ultimately to support the TA of youth with histories of trauma.

3.2.3. Results of Evaluations of TIC Practices and Policies

The results of some evaluations provided information on implementation and on youth’s and staff’s perceptions. LEAP (Jobs for America’s Graduates [JAG] and Back on Track [BoT]) seeks to address trauma in youth and help them get a high school equivalency or a job, gain life skills and create a support system. The evaluation of LEAP implementation revealed a few takeaways for implementing TIC initiatives: find and retain staff to whom youth can relate; partner with organizations as a recruitment strategy for youth and as a way to connect them to services; and flexibility when delivering programs to promote youth engagement [66,67].

The TRM, anchored in attachment, trauma, criminology, and neurology, identifies and addresses with a trauma-informed lens the needs of TAY aging out of care by establishing connections between youth and agencies and ensuring staff understand trauma and its impact. Staff perceived that it helped youth develop confidence and self-esteem, think independently and improve their life skills [65]. While staff found the TRM helped, they mentioned they lacked confidence in applying the model, which underscores the importance of training, according to Baker and Barragan [65].

As for staff training, staff expressed that time for reflection, open dialogue and awareness of ‘success stories’ are important [64]. Staff suggested that the following themes should also be part of trauma-informed training: understanding triggers, conflict resolution skills and positive coping mechanisms, supporting self-regulation, de-escalation techniques, communication, staff burnout considerations, vicarious trauma, and self-care [64]. Furthermore, staff found that techniques shared during TIC training for supporting self-regulation and de-escalation were effective [64].

Effects of TIC initiatives on TA outcomes and costs. First, the evaluation of the LEADS program indicated that intensive services positively influenced educational progress and academic success in youth [59]. Similarly, the two evidence-based models from the LEAP initiative revealed positive effects on youth’s educational and social functioning outcomes. More precisely, youth participating in BoT showed an increased likelihood of pursuing post-secondary education, while those involved in JAG had an increased understanding of career pathways and job credentials [66,67]. As such, most youth involved in JAG (76%) engaged in school or work in the first six months of the follow-up phase, and some obtained high school credentials. In addition, results indicated that JAG helped youth create a support system and gain life skills [66,67].

Assessment of transitional living programs (TLPs) based on the Sanctuary model, a trauma-informed organizational approach [68], revealed positive results in terms of educational and employment outcomes in youth, but findings were very mixed for mental and social functioning [63]. Over a six-month period, participating youth’s scores trended upward on the Achenbach System of Empirically Based Assessment (ASEBA) Adaptive Functioning scales for jobs and friends, and their positive perceptions of community living environments increased. Most youth involved in TLPs reached their employment, housing, and financial goals towards the end of the six-month study [63]. However, the assessment of the TLPs also showed an increase in social withdrawal symptoms and increasing trends for substance use and for all ASEBA DSM-oriented scales – though they remained in the normal range – except for the depression symptoms scale for which a decreasing trend was observed over the six-month period studied [63]. Lastly, only one study evaluated the costs of a TIC initiative (LEAP) that supports the TA. The estimated cost for all phases ranged from $5,300 and $7,300 per youth [66,67]. However, costs could not be compared with those of other initiatives, and cost-benefit or cost-effectiveness was not evaluated.

4. Discussion

The objective of this scoping review was to explore the extent of the literature on the potential of TIC to support the TA of trauma-exposed youth. We identified 19 references (1) highlighting the need for or importance of a TIC approach to support the TA; (2) describing TIC practices and policies supporting the TA; and (3) evaluating TIC initiatives supporting the TA. We propose a schematic figure to summarize the extent of the literature on the topic (see Figure 2). References documented a total of 10 models or initiatives, half of which underwent evaluation. We also noted recurrent or important components of TIC initiatives aimed at supporting the TA: staff training and support; collaborative and multidisciplinary work; systemic and organizational changes; acknowledgment of the interrelation between trauma and its impacts; and a strength-based and youth-focused approach, which are discussed below. While the review gives an overview of current empirical knowledge on the potential of TIC for supporting the TA, it also points out future lines of work.

4.1. Acknowledging and Responding to Trauma

The reviewed literature strongly supports that acknowledging and responding to trauma is essential [57]. TAY [50,51,56,63], foster families [56] and service providers [52,53,56] report there is a need for trauma-informed services and programs to support the TA [54,61,62], despite the fact they may not be widely available (Harder et al., 2020). Many of the included references indicate that youth need to receive services that acknowledge the interrelation between trauma and its impacts on development and functioning and that treat trauma symptoms in a way that is developmentally sensitive, strength-based and youth-focused [50,51,56,63,65]. This could, in turn, positively support education and employment; economic and living situation; and mental health and social functioning during the TA [19,20]. Moreover, given that TIC actively seeks to resist re-traumatization, it could prevent or reduce system-induced trauma.

4.2. The Definition of TIC and Its Systemic Nature: Strengths and Challenges

Although the SAMHSA’s definition of TIC is widely accepted, we uncovered that, while services and programs may define themselves as trauma-informed, TIC may be inconsistently applied. In addition, it may include a variety of components or principles, making it complex to define and operationalize within the context of the TA, although the review led to the identification of “core” components in Figure 2, one of which is the systemic nature of TIC. Although this systemic nature may create challenges when it comes to operationalizing TIC into models and programs [69,70,71], the reviewed references emphasize that organizational changes are key to the systemic nature of TIC and important for supporting the TA of trauma-exposed youth [54,59,61,62]. Systemic and organizational changes in the context of TIC would notably encompass collaborative and multidisciplinary work [63,66,67]. The references reviewed highlighted the importance of collaboration and partnerships among stakeholders [62,67] and among different types of organizations (e.g., education and housing organizations, institution and community organizations) [49]. Partnerships could help to connect youth with services [49]. Accordingly, a review of scoping reviews [72] indicated that trusting relationships and partnerships between youth and service providers, and between service providers, are key to successful TIC initiatives. Yet, trusting service providers is a challenge for youth who have experienced system-induced trauma. Phillips et al. [7] add that multidisciplinary work is best suited to addressing youths’ complex and multiple needs related to childhood trauma. Thus, although the references reviewed bring attention to the importance of systemic and organizational changes, notably through collaborative and multidisciplinary work, they also acknowledge the challenges it poses for operationalization and therefore for evaluation [54,59,61,62,65].

4.3. Implementation of TIC Initiatives Through Staff Training and Support

We reviewed 10 TIC models or programs that aimed to support the TA of trauma-exposed youth, as well as three documents outlining principles or recommendations for best practices [57,61,62]. Most models and programs involved some type of staff training to support implementation [e.g., [54,58,656667]]. This is typical in the field [6,69,70,71,73] and, interestingly, could further support collaborative work and partnerships [72]. This review provides indications of what and how staff training could eventually support the TA of trauma-exposed youth. Moreover, in addition to staff training, the importance of ongoing training, supervision and support is highlighted in many of the references reviewed [52,53,61], as well as in previous reviews on TIC [69,70].

4.4. Effects of TIC Initiatives

While we reviewed 10 TIC models of programs, half of them were not evaluated and those that were evaluated only once [59,60,63,65,66,67]. Therefore, at the moment, there is no one TIC model or program that is deemed effective or recommended for supporting the TA of trauma-exposed youth based on our review. Rather, models and programs show positives and promising effects on TA outcomes, and we have identified key components that were found to be important (see Figure 2). Studies indicate positive effects on youth outcomes related to education and employment and, to a lesser extent, to economic and living situation, and mental health and social functioning. Implementation initiatives also resulted in positive effects on professional knowledge, attitudes and practices [65]. However, some of the models and programs that have been evaluated revealed some mixed findings [66,67]. Results of evaluations are to be considered in light of the fact that implementation of TIC initiatives is seldom described or assessed. This makes it difficult to determine whether mixed findings reflect the actual efficacy of the programs or services evaluated, or stem from issues with implementation.

4.5. Strengths, Limitations and Future Directions

This review drew upon a recent and comprehensive literature search (including gray literature and nine databases). The extensive search for gray literature yielded 43 additional references, of which eight were included, thus the search for gray literature was deemed crucial in this review to increasing our pool of references, to broadening our scope, and to incorporating available empirical knowledge on TIC within the context of TA. Despite its innovative research questions and strengths (e.g., search strategy, gray literature search, duplicate screening), this scoping review also has limitations. It does not include an assessment of the methodological quality of the references, though this assessment is typically not expected in scoping reviews [42,43]. While screening was performed in duplicate, extraction was not. However the tool was pre-tested, and the extraction was verified by the principal investigator in accordance with Pollock et al. [74].

The included references present strengths and limitations as well, giving indications for future studies on the topic. Some references relied on alternative methods to explore the potential of TIC for supporting the TA (e.g., formulation of principles, clinical perspective) [56,57,61], and most did not adopt quasi-experimental or experimental design, precluding any initial affirmations on the efficacy of TIC to support the TA. Although some studies were not experimental, they included repeated measures of outcomes [63,66,67], and the outcomes considered were multidimensional – education, life skills, employment, housing, sense of community – which is in accordance with the TA literature and reiterates the importance of multidisciplinary work when working with TAY.

We observed that some types of methods were more common for some reference categories. References discussing the importance of or need for TIC were mostly qualitative (none was solely quantitative); those describing practices or policies were mostly descriptive only; and references that assessed TIC initiatives were mostly mixed (none was solely qualitative). Although qualitative and quantitative methods are expected and deemed appropriate for exploring TAY’s needs and assessing initiatives, respectively, one can argue that we only have a partial account of the phenomena. We also note small samples, notably in references using qualitative methods. Although some of the studies relying on quantitative methods included large samples, information provided on methods or outcomes were very limited in some cases [e.g., [59]].

Most of the work reviewed was recent but mainly from the U.S., which limits the generalization of findings for other socio-cultural contexts where systems and policies for TAY are different. Studies conducted in a variety of socio-cultural contexts are paramount, given that the TA is influenced by the context in which it occurs [75,76]. Overall, the literature would benefit from adopting quasi-experimental or experimental design, increasing sample sizes in studies, and providing detailed information on methods and results, as well as on TIC operationalization and implementation. Implementation and results of programs could be evaluated using the Bargeman et al. [77] term “intervention methodology” to specify to what extent they could be effective or recommended for supporting the TA of trauma-exposed youth.

In conclusion, it is interesting to note that the main findings from this review are, overall, in line with the key components of successful TIC implementation in youth settings identified by Bryson et al. [69] in a systematic review, that is: (1) the importance of organizational leadership; (2) the need to support staff; (3) the relevance of listening to individuals and families; (4) the importance of reviewing data and outcome towards improvement; and (5) the need to align policy and practice. Our findings in the context of TA echo these components, though the importance of families and data and outcome review are themes that are less present in the reviewed references. This review shows that the literature on the potential of TIC for supporting the TA is emerging and needs to be expanded to ascertain the efficacy of TIC for this specific purpose. At the moment, TIC is at least promising in terms of transforming services and supporting trauma-exposed youth through the challenges they face during the TA.