The current scoping review aimed to explore the overall experiences of adolescents’ self-engagement and to identify factors that are important to facilitate self-engagement in mental health treatment. The results were grouped into five themes: the therapeutic alliance, the need for active engagement in treatment, different experiences due to time of data collection, treatment context and healthcare system, and adolescent-caregiver interaction. Our major findings indicate a broadening conceptual understanding of self-engagement, implying that self-engagement is not static, but influenced by all the five themes. Our findings support the review of Hawke and colleagues [4], which stated that mental health services need to integrate adolescents’ voices in terms of self-engagement at all levels of an organization. This is in accordance with the proposal by the WHO [9, 10] that adolescents’ needs, wishes and preferences must be a central factor in informing and designing their treatment [11].

This scoping review of 19 studies demonstrates that there is limited knowledge on the topic of self-engagement in the field of PCC regarding adolescents in mental health treatment, confirming previous findings that adolescents are rarely actively involved in their mental health treatment [15, 20]. Our scoping review contributes to the existing literature by including adolescents’ voices for a wider range of self-engagement in treatment. Thus, the findings imply that self-engagement can be seen as a broad and complex concept, influenced by individual factors, contextual factors and the relationship between adolescents, caregivers and HCPs. This multilevel complexity may partly explain why mental healthcare has been slow to respond to recommendations made by adolescents.

HCPs who elicit adolescents’ perspectives on their mental health symptoms may be more likely to increase adolescents’ self-engagement; it will then develop in dynamic interaction between contextual factors and the person’s unique personality and symptom burden [12, 16]. In this connection, adolescents in the studies consistently mentioned the importance of the therapeutic alliance. This main theme fits remarkably well with the principles of PCC, which emphasize the ability of HCPs to be respectful and supportive, and to listen to adolescents’ needs [1, 2]. This finding also addresses the complexity of the role of caregivers in adolescents’ mental health treatment. This indicates that the principles of PCC need to be applied in a way that meets adolescents’ expectations that adults will listen to them, appreciate them and reflect on their opinions [6]. Adolescents’ concerns about privacy and confidentiality in interaction with caregivers reflect possible conflicts in the adolescent-caregiver relationship. At the same time, caregivers need to be involved to support adolescents in mental health treatment [41]. PCC approaches recognize the importance of both adolescents’ and caregivers’ perspectives but balancing them is challenging [15]. The findings in this study are in line with the review by Lynch and colleagues [5], indicating that HCPs need to prioritize the core components of trust and confidentiality as essential in the provision of meaningful mental health treatment for adolescents.

The time of data collection is one of the five main themes in our review. Data were collected at three distinct time points: before, during, and after treatment. These time points revealed different adolescent experiences related to self-engagement. To ask adolescents at the beginning of treatment about their expectations for the upcoming treatment could lead to less uncertainty and increased understanding of their perspectives on their problems. Information and explanations during treatment, especially at the start and at the end, were of importance. Adolescents who were interviewed at the end of or after treatment reported feeling unsure about their future and had a sense that the treatment was terminated prematurely. In this way, self-engagement can be understood as an ongoing process. This finding is consistent with the review conducted by Dixon and colleagues [16], emphasizing the importance of patients’ sustained self-engagement throughout treatment.

The findings underline the importance of treatment context and daily structure for self-engagement. Adolescents wanted mental health treatment settings to be more relaxed and informal, which is a consistent finding in the literature on mental health services in general [14].

In acknowledging the transferability of findings, it is essential to consider variations in healthcare systems and cultural factors. While self-engagement in mental health treatment is advocated as an adolescent’s right to live a fulfilling adult life [8,9,10], its realization depends on the complexity of healthcare systems and cultural nuances.

The results of this review support mental healthcare based on a PCC approach [1, 2], involving values such as acceptance, respect, professionalism, communication, and acceptance [6]. The findings clearly show that adolescents want to be involved in their mental health treatment. Adolescents express a clear interest in providing constructive feedback to improve the quality of their care. Moreover, they emphasize the importance of active participation in decision-making processes. In fact, a need for active self-engagement in treatment was found to be a core value across the five themes. The UN Convention on the Rights of the Child states that adolescents should have the right to express their views and their opinion should be given due weight in all matters affecting them [8].

As findings from the current review show, self-engagement is considered essential for PCC [4]. This review provides insight into the complexity of integrating active self-engagement for adolescents in mental health treatment. HCPs need to be aware that active self-engagement is a broad and complex concept. In order to succeed, HCPs must focus on all the factors involved: individual, contextual, and relational between adolescents, caregivers, and HCPs. Mental health treatment without adolescent self-engagement can lead to worse clinical outcomes and symptom relapse [16]. A clinical contribution from this review is further attention to improvement of HCPs’ communication skills adapted to adolescents’ needs. On a practical level, HCPs should make efforts to listen to adolescents’ own stories and involve them in every step of their treatment [4]. Further, HCPs need to find out what level of caregiver involvement in treatment is desired by the individual adolescent. HCPs also need also to be aware of the legislation that addresses mental healthcare for adolescents and caregivers [6]. This knowledge is crucial to ensure that HCPs navigate legal and ethical considerations effectively when providing care to this population. It will safeguard the rights and well-being of both adolescents and their caregivers.

Our review demonstrates the limited knowledge of PCC in mental health treatment for adolescents. Hence, we suggest further research on adolescents’ voices regarding the broad and complex concept of self-engagement. Moreover, further knowledge is needed to explore the interaction between individual, contextual and relational factors. Cultural background awareness and provision of culturally competent care may be one way to enhance self-engagement [13, 16]. One person-centered tool is the Cultural Formulation Interview (CFI) published in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) [50]. Research shows that use of the CFI is an important step toward PCC [51], as it improves the therapeutic alliance and contributes to subjective exploration of the patient’s health narrative [52, 53].

Further research on specific PCC interventions such as the CFI may strengthen understanding of and evidence for active self-engagement by adolescents in mental health treatment. Due to the limited research on adolescents’ self-engagement, there is a need for a diversity of methods in different clinical contexts. Important here are longitudinal research throughout the treatment process and targeted research on confidentiality to enhance adolescent-caregiver interaction. In addition, further research should explore HCPs’ and caregivers’ voices on self-engagement in mental healthcare to complement these results.

The advent of new technology means that self-engagement can be further improved through the use of digital tools [17]. In our review, adolescents identified benefits of e.g., text messaging to access help on their own [44], indicating that digital tools to increase information and access to support in mental healthcare are an area for future research.

This review was conducted using rigorous and systematic methodology. Nevertheless, the review has some limitations. The literature in the area of PCC in adolescent mental health treatment proved to be limited, which necessitated a broad search, including gray literature. While focusing on breadth over depth, this review may constitute a basis for future systematic reviews to explore in depth specific topics identified here. However, an initial tentative research question would have been of value for a more clearly defined search and for clarity in the inclusion criteria. While broad techniques were employed to identify relevant studies, using text-based search strategies in combination with manual backward citation searching and co-citation searching, we acknowledge that we could have included forward citation searches. This could have yielded recently published material not captured by the text-based search. However, searching for gray literature and the co-citation searches should to some extent compensate in covering recent publications.

Including only qualitative studies in this review may have weakened its scope by overlooking quantitative trends and patterns that provide a more comprehensive understanding of this field. Including both qualitative and quantitative studies could have resulted in more balanced and thorough insight. However, in such an under-researched area a focus on qualitative studies was deemed essential, in terms of the contributions of qualitative methodologies and the need for a more in-depth analysis.

The clinical contexts in this review were dominated by outpatient clinics. Only three studies recruited adolescents from inpatient units. The majority of the studies originated from the United Kingdom, particularly England, followed by Australia. There was variation in the timing of data collection. Only one study was longitudinal, with interviews at three different points during treatment. In some studies, caregivers were part of the data collection, but their level of participation differed. This varying role might have affected how adolescents responded, but it is difficult to confirm this. In addition, the included adolescents had a wide age range and a variety of mental illnesses. Despite this, adolescents’ preferences for self-engagement in mental health treatment seemed to demonstrate more similarities than differences. This should enhance transferability of the findings to a variety of mental healthcare contexts for adolescents.

Although several studies in the identification and selection process reported on adolescents’ perspectives, it is important to note that the age limitation (12–18 years) may have resulted in the exclusion of studies focusing on children or young adults that could be of relevance to adolescents. However, some studies included adolescents under 12 years or above 18 years. We chose to include these studies since most of the participants were in the age range 12–18 years. Additionally, any attempt to standardize methods of data collection in this group may encounter difficulties because of the wide age range of the adolescents. In Ronzoni and Dogra [46], the age range of the adolescents was 6–18 years. A method suitable for a six-year-old may not be appropriate for an 18-year-old, yet the same method is used for a wide age range in many studies. Only five studies used a combination of methods to ascertain adolescents’ views. Worrall-Davies and Marino‐Francis [18] highlighted the importance of using more than one method when eliciting adolescents’ views of mental health treatment, and of ensuring that the research methodology is appropriate to the particular developmental level of the adolescent. In this review, it is possible that the adolescents included were those who had a particularly high level of engagement in mental health treatment. Presumably, adolescents who drop out of mental health treatment were not included in the studies as they are under-represented in the literature [3]. Future research may consider splitting the age range between younger and older adolescents given developmental variations. This approach could provide a more comprehensive understanding of self-engagement, acknowledging potential differences in how younger and older adolescents are able to articulate their views and opinions.

Finally, it is important to acknowledge that the systematic search used to identify studies for inclusion in this review was conducted in January 2022, implying that relevant studies published later were not included.