The World Migration Report 2022 stated that 1 in 30 people globally resides in a country that differs from their birth country and that this number has increased over the last 5 decades [1]. With most migration streams flowing from low-income to high-income countries [1], many migrants experience differences between their heritage and host cultures.

Previous research into acculturation (ie, the impact of interacting with other cultures on an individual) has highlighted 2 key issues. First, the issue of cultural maintenance, which is the extent to which heritage cultural identity is considered important and practices are continued. Second, the issue of deciding on the extent of contact and participation (ie, interacting with the host culture or remaining within heritage cultural groups) [2]. Based on these 2 issues, Berry and Sam [2] proposed four acculturation strategies: (1) integration (whereby heritage culture is maintained while seeking to interact with other groups), (2) assimilation (whereby heritage culture is not maintained while interactions with other groups are sought), (3) separation (whereby heritage culture is maintained while wishing to avoid interactions with other groups), and (4) marginalization (whereby cultural maintenance is perceived as difficult, and little interest is demonstrated in interacting with other groups).

A considerable amount of research has examined the association between acculturation and mental health outcomes, including several systematic reviews [3,4] and meta-analyses [5,6]. However, despite age being identified as a key component of the association between acculturation and mental health [6], no review to date has examined how cultural maintenance affects mental health outcomes in migrant adolescents (aged 10-24 years [7]).

Marked as the transition into adult life, adolescence is a life phase of great change. Adolescence has been identified as “a second sensitive developmental period in which puberty and rapid brain maturation lead to new sets of behaviours and capacities that trigger or enable transitions in family, peer, and educational domains, and in health behaviours” [8]. As these transitions affect a child’s future health outcomes [8], understanding factors shaping adolescents’ mental health outcomes is important to support their healthy development.

Even though Viner and colleagues [8] caution that their ecological analysis does not imply causality, they found that “national wealth, inequality, and education had the largest effect sizes...and were associated with the largest range of health outcomes in young people.” They further identified that similar factors, related to family, peers, and education, can help protect adolescents’ health across countries [8].

Adolescents with a migrant background—specifically, first- or second-generation migrants—are faced with the added complexity of navigating this intense transitional phase within a multicultural or multilingual context. In fact, some research has identified a migrant background to be a predictor of poor mental health outcomes in adolescents [9]. A study in a regional child and adolescent mental health service in Australia reported that the majority of mental health support was needed by Aboriginal youth, followed by Asian-European heritage youth, with the researchers pointing at the role loss and disconnection from heritage culture may play in poor mental health outcomes [10]. Hallett and colleagues [11] had even more poignant findings related to Indigenous cohorts, identifying native language knowledge as correlating with a reduction in Indigenous youth suicide in Indigenous communities in Canada. The extent to which a similar effect of language or culture maintenance on mental health outcomes may be evident among adolescents with a migrant background remains unknown.

There is a large body of adolescent mental health research studying the effectiveness of interventions [12], help-seeking behaviors [13,14], and the applicability of information technologies [15]. Müller and colleagues [16] conducted a scoping review on the effect bilingualism has on family and child well-being, which provides valuable insights. However, rather than specifically looking at bilingualism, we are interested in research investigating the association between heritage culture or language knowledge and mental health outcomes in migrant adolescents.

This scoping review will provide a better understanding of migrant adolescents’ ecological systems and identify modifiable risk factors associated with optimal mental health outcomes. This knowledge will inform future research leading to improved interventions and policies that contribute to improved mental health outcomes in migrant adolescents.

This protocol outlines the methodology of a scoping review that will address the following questions:

(1) What is the focus, scope, and nature of quantitative empirical research investigating heritage cultural maintenance, including language maintenance, and mental health outcomes in adolescents with a migrant background worldwide?

(2) What effects, if any, do cultural and linguistic maintenance or disruption have on migrant adolescent mental health outcomes?

This protocol adheres to relevant sections of the Preferred Reporting Items for Systematic Review and Meta-Analyses–Protocols (PRISMA-P) [17], which we provide in the form of a checklist [18] in Multimedia Appendix 1.

We conduct the scoping review following the methodological framework outlined by the Joanna Briggs Institute [19], which is based on the Arksey and O’Malley framework [20] and Levac and colleagues’ [21] elaborations. Reporting will follow the PRISMA Extension for Scoping Reviews (PRISMA-ScR) [22].

For an overview of the scoping review’s inclusion and exclusion criteria, please refer to Textbox 1.

A total of 11 electronic databases were searched on April 20, 2021, from the beginning of each database.

The electronic databases are APA PsycArticles Full Text (coverage from 1894); Embase Classic+Embase (from 1947); Ovid MEDLINE All and Epub Ahead of Print, In-Process, In-Data-Review and Other Non-Indexed Citations and Daily (from 1946); Ovid MEDLINE All (from 1946); APA PsycInfo (from 1806); University of Melbourne full-text journals; Science Citation Index Expanded (from 1900); Social Sciences Citation Index (from 1900); Arts & Humanities Citation Index (from 1975); Scopus (from 1970); Linguistics and Language Behavior Abstracts (from 1973).

We will also screen reference lists to identify relevant studies that the electronic search might not have identified.

The search strategy was shared with a university librarian, who provided feedback to further tailor the search strategy to each database. After the search of the electronic databases, the search results’ titles and abstracts are screened in a Microsoft Excel (Microsoft Corp) spreadsheet, applying the inclusion and exclusion criteria as outlined by this protocol. To be eligible for inclusion, studies must fulfill all 4 categories (coded in the search query with “AND”). Within each category, studies must meet at least 1 search term (coded in the search query with “OR”). The search query syntax was adjusted to meet specific database requirements. An example of the search command used for Ovid MEDLINE All is provided in Table 1.

The primary focus of this review is to understand the research investigating the association between cultural or linguistic maintenance and mental health outcomes in migrant adolescents. As we are investigating a multidisciplinary field of study, there is a possibility of studies having heterogeneous research perspectives and findings. We aim to be rigorous in including only studies that fulfill all 4 search categories. When studies meet criteria in all 4 categories, we will also report on findings that may directly or indirectly affect the association between cultural maintenance and mental health outcomes, such as the effect of host cultural orientation, as well as moderating or mediating factors. This will allow us to understand the identified phenomena better.

We will provide a descriptive overview of included studies, stating sample size, age, and location, as well as mental health outcomes and cultural or linguistic maintenance factors measured. We will then provide a structured, narrative summary of study findings about our second research question in text and—depending on feasibility—table form. We will report commonalities and differences in findings, explore potential hypotheses, and identify gaps in the research. We will not assess the quality or bias of studies, grade evidence, or include a quantitative synthesis of evidence.

Our review does not require ethical approval, as it reports on findings from published studies that have already obtained ethics approval. We will disseminate the findings of the scoping review through a peer-reviewed journal article and national and international conference presentations.

This scoping review protocol outlines a rigorous and replicable methodology for the review of empirical research investigating cultural maintenance, including language maintenance, and migrant adolescent mental health outcomes. To our knowledge, no comparable study has been conducted. The search conducted in April 2021 returned 2569 results.

We will report results in the scoping review following the PRISMA-ScR. Our search strategy included 11 relevant academic databases, as well as a grey literature search. We are screening titles and abstracts and will extract data from included studies using predefined charting items. This will allow us to compare the nature of study elements and identify trends and gaps in the existing literature.

We will also extract relevant findings to address our second research question and present the results in a narrative summary, which will possibly result in the suggestion of hypotheses or research questions that could inform future research or systematic reviews. The preliminary review of literature has shown that rather than inferring causality, it is important to interpret findings considering adolescents’ context. Some studies use an ecological approach [23] and, depending on our results, we are planning to use a similar approach to contextualize results.

Some existing reviews that were not adolescent-specific identified biculturalism to be advantageous on adjustment [5], and child well-being benefiting from bilingualism at home [16]. Our study will contribute to the existing literature, providing a better understanding of language or cultural maintenance, while specifically focusing on mental health outcomes in migrant adolescents who are and will constitute large cohorts within society.

Even though we conducted the search worldwide, we used only English search terms, limiting our results to studies with English titles, abstracts, and keywords. Included results that were written in another language are reviewed by a researcher proficient in the language. Another limitation of this study is that evidence will not be quantitatively synthesized in this review, as we will not do a quality or bias assessment of studies. Moreover, this highly multidisciplinary field of study leads to heterogeneous results from various disciplines (ie, psychology, adolescence research, and linguistics), which slows down the review process.

The scoping review outlined by this protocol will provide a more cohesive understanding of existing multidisciplinary research into cultural and linguistic maintenance and mental health outcomes in migrant adolescents. This will provide a more comprehensive understanding of how youth mental health outcomes and cultural factors, including linguistic factors, have been investigated to date, and what future investigations may be required. The outlined scoping review therefore plays an important part in improving migrant adolescents’ mental health outcomes.