Adolescent mental health has become a major global public health concern, with rising rates of anxiety, depression, and emotional dysregulation among young people [1, 2]. Recent reviews highlight a sustained increase in mental ill‑health over the past decades, driven by social, educational, technological, and environmental pressures, and further intensified by the COVID‑19 pandemic [3, 4]. Evidence from cross‑national studies indicates that, although countries differ in their socioeconomic contexts and specific risk factors, adolescent mental health problems show a broadly similar pattern worldwide. Internalising symptoms, general psychological distress, and bullying emerge as consistently prevalent issues across regions, suggesting that adolescent mental ill‑health is a widespread global concern rather than a phenomenon confined to particular contexts [5]. Overall, findings converge on the importance of equipping educators and institutions with evidence‑based strategies for early detection and timely intervention to support adolescent wellbeing [1–5].

Multiple individual, relational, and social determinants converge to heighten adolescents’ vulnerability to psychological distress. Risk factors include exposure to adverse childhood experiences, such as abuse, neglect, and household dysfunction, as well as chronic academic stress, social isolation, and cyberbullying [6]. An umbrella review found that low self-esteem, poor family functioning, and lack of social support are consistently associated with increased risk of self-harm and suicidality in adolescents [7]. Generational shifts in digital media use and reduced face-to-face interactions have been associated with higher levels of social anxiety and depressive symptoms among youth [8]. Cultural and socioeconomic disparities further increase these risks, with marginalized adolescents often facing systemic barriers to accessing mental health care [5]. These findings highlight the need for early, context-sensitive interventions that address both individual vulnerabilities and broader environmental stressors.

School-based interventions are widely implemented as a primary approach to promoting adolescent mental health, offering accessible and preventive support within educational settings [8]. In Spain, programs such as “Awakened Schools” (Escuelas Despiertas), a mindfulness and compassion-based initiative, have shown promising results in reducing psychological distress and improving emotional regulation among secondary school students [9]. These interventions often face challenges related to implementation fidelity, teacher training, and institutional support, which can limit their scalability and long-term impact [8].

Digital mental health interventions have emerged as a complementary and increasingly popular approach, providing formats that are scalable, adaptable, and engaging for adolescents. A recent systematic review found that digital tools—such as apps and online platforms grounded in cognitive-behavioral therapy (CBT) can effectively reduce symptoms of anxiety and depression in youth, particularly when integrated into school curricula. However, barriers such as digital literacy gaps, privacy concerns, and limited personalization remain significant challenges [8].

Recent research emphasizes that digital innovation—such as cloud-based platforms, AI tools, and data-driven learning environments—can support transformative learning when integrated into coherent pedagogical models and institutional strategies. These technologies also introduce new demands for educators’ digital health and well-being. Advances in cloud infrastructures, virtual labs, and HyFlex models have been identified as enablers of scalable, personalized, and collaborative learning [10]. At a systems level, international reports highlight that the integration of digital technologies in education remains uneven, and that meaningful transformation depends on designing supportive ecosystems that address infrastructure, governance, and teacher professional conditions [11]. In parallel, recent European guidelines on wellbeing and mental health in education emphasise whole‑school approaches that combine digital competence, safe use, and staff support within a comprehensive framework involving the entire school community [12]. Evidence from recent reviews also shows that digital interventions can improve mental health outcomes when they are well‑designed, context‑adapted, and supported by educators and institutions [8]. Taken together, these findings frame our study within global efforts to align educational technologies with teachers’ professional functioning and overall well-being.

Promoting core psychological strengths—such as resilience, emotional regulation, and self‑esteem—is essential for supporting adolescent mental health. Evidence shows that adaptive emotion regulation strategies, particularly cognitive reappraisal and acceptance, strengthen resilience and protect against anxiety, depression, and emotional distress [13, 14]. Likewise, self‑esteem consistently emerges as a protective factor associated with healthier coping, reduced risk behaviours, and better psychological adjustment during adolescence [15]. Building these capacities via digital platforms enables scalable, preventive mental health strategies for youth.

Despite the growing number of school-based mental health initiatives aimed at adolescents, few interventions have focused on the formative stage of those who will become primary providers of emotional support in educational settings: future teachers. The proposed intervention stands out by embedding mental health promotion within the academic training of pre-service educators, specifically through the course “Learning and personality development” (Aprendizaje y desarrollo de la personalidad) in a master’s program. Unlike most existing programs (which tend to prioritize external strategies for student management or offer general mental health literacy), this initiative adopts an introspective, experiential approach. It emphasizes the development of personal psychological resources such as emotional regulation, self-awareness, and psychological flexibility, based on the principles of acceptance and commitment therapy (ACT) [16, 17]. This theoretical foundation is particularly relevant, as ACT has demonstrated efficacy in enhancing well-being and reducing stress among educators [18], yet its integration into teacher education remains scarce. The intervention uses digital tools to support self-reflection and emotional skill development, addressing a gap in the literature where digital mental health programs for teachers-in-training remain underexplored [19]. By emphasizing the inner development of future teachers as a foundation for promoting adolescent mental health, this approach provides a scalable, evidence-based contribution to educational practice.

Secondary school teaching is increasingly characterized by high levels of occupational stress, emotional exhaustion, and burnout, driven by workload, curricular change, limited institutional support, and sustained emotional demands [20]. Evidence indicates prevalent symptoms of anxiety, depression, and depersonalization among secondary teachers, with documented consequences for well‑being and performance [21, 22]. Post‑pandemic surveys further suggest that up to 78% of teachers have considered leaving the profession due to stress and burnout [23]. Within this context, the intervention (centered on introspection and ACT) was designed to strengthen future educators’ competencies for supporting adolescent well-being while promoting proactive strategies for managing their own mental health, thereby addressing a documented gap in teacher training [20–23].

The mental health of educators is a determinant of classroom climate and student outcomes. Teacher distress is associated with greater mental health difficulties among adolescents, particularly under conditions of perceived low safety and support at school [24]. Burnout and emotional exhaustion are linked to challenges in classroom management and a less supportive socio‑emotional environment, with effects on student engagement and development [25, 26]. Interventions that promote introspection and psychological flexibility in teachers, therefore, have dual value: they improve educators’ psychological functioning and contribute to healthier learning environments and student mental health.

Schools function not only as educational settings but also as key contexts for psychological support, where teachers influence students’ emotional and cognitive development. Preparing future educators to identify and respond to mental health needs is therefore essential. Providing tools that strengthen introspection and psychological resilience can enhance their ability to create supportive learning environments. In this regard, digital health interventions grounded in evidence-based approaches offer scalable strategies for early detection and prevention. Integrating these technologies into teacher education programs may represent an important step toward promoting adolescent mental health.

Initial teacher education often provides limited preparation for pre-service teachers in introspective and self-regulatory competencies essential for creating psychologically safe and responsive classrooms. While many candidates possess theoretical knowledge of mental health, they frequently lack experiential skills to model adaptive coping, regulate emotions, and manage emotionally demanding situations. Scalable approaches that extend beyond mental health literacy to cultivate psychological flexibility and self-awareness are needed. These competencies enable teachers to de-escalate conflict, tolerate discomfort, act in accordance with professional values, and maintain supportive learning environments. However, few initial teacher education programs explicitly address psychological flexibility through structured, experiential practices grounded in established therapeutic frameworks. Detailed descriptions of program logic and content remain scarce, and empirical evidence involving pre-service teachers (particularly within European and Spanish contexts) is limited. Existing digital initiatives for teacher training have primarily focused on instructional or managerial skills rather than sustained experiential self-reflection [27].

To address these gaps, this study develops and evaluates La Casa Vital (The Vital House), a digital, introspection‑based program for future secondary teachers. Using a symbolic house metaphor aligned with the ACT Hexaflex [16, 17], the study (1) presents the program’s theoretical framework, structure, and components to facilitate implementation and replication, and (2) examines short‑term pre–post changes in psychological flexibility processes (acceptance, cognitive defusion, mindfulness, self‑as‑context, values, committed action) and in introspective capacity among a cohort of Master’s students.

By prioritizing the intrapersonal development of future teachers and delivering content through a modular digital format, this study explores a theoretically grounded and potentially scalable approach for integrating mental health promotion into initial teacher education. The combination of ACT-based processes with professional identity formation may offer conceptual and practical relevance, providing preliminary insights that could inform future research and implementation within Spain and comparable educational contexts. The manuscript is organized as follows. First, the introspection‑based program developed for pre‑service teachers is described, as it constitutes the core contribution of this study. Second, the study design, participants, and measurement instruments are detailed. Third, the intervention results and their implications are presented. Finally, limitations, practical applications, and directions for future research are discussed.

The pre–post comparison of scores on the two dimensions of the SRIS showed distinct patterns of change. Participants exhibited a statistically significant increase in introspective capacity from pre to post‑intervention (pre: M = 25.19, SD = 7.83; post: M = 27.14, SD = 7.10; t = –2.715, p = 0.008), suggesting an association between program participation and a greater ability to examine internal experiences. By contrast, self‑reflection scores remained stable across the program (pre: M = 33.25, SD = 7.80; post: M = 33.64, SD = 7.03; t = –0.505, p = 0.615) [29].

Table 2 shows the pre–post differences in the six components of the Hexaflex model: acceptance, cognitive defusion, mindfulness, self-as-context, values, and committed action. Significant improvements were observed in five components: acceptance (p = 0.019), mindfulness (p = 0.014), self‑as‑context (p < 0.001), values (p = 0.048), and cognitive defusion (p = 0.034). Committed action aligned with values was the only Hexaflex component in which no statistically significant differences were found (p = 0.40). These results suggest that the intervention was associated with measurable changes in most psychological flexibility processes.

Figure 2 displays the absolute pre–post differences (Δ = post − pre) on the x‑axis, with annotations for Δ, p, and the within‑subject effect size (dz), thereby highlighting the most robust improvements. As shown in Figure 2, effect sizes for pre–post changes fall within the small‑to‑moderate range, with Cohen’s dz values from 0.22 (small) to 0.42 (moderate), indicating modest but consistent gains following the intervention. The largest effect size is observed for self‑as‑context (dz = 0.42), followed by introspection (dz = 0.30).

This study presents the implementation of an introspection‑based teaching methodology delivered through a digital platform (“Vital House”), in which each room symbolizes a different life domain. The program was offered to students enrolled in a Master’s in Teacher Training and examined using a single‑group pre–post design, which limits causal inferences. In this exploratory context, pre–post analyses suggested preliminary indications of change in introspection and in several components of the ACT Hexaflex model [16, 17], except for committed action aligned with values. Moreover, in a previous investigation on the same Vital Home program [29], in addition to the aforementioned changes in introspection, significant increases were observed in intrinsic goal orientation, control of learning beliefs, and self‑efficacy for learning and performance. These findings should be interpreted cautiously, as potential confounding influences, such as concurrent course content, maturation, or repeated‑testing effects, cannot be ruled out. The broader aim of the Vital House program is to support teachers’ psychological well‑being and to strengthen their capacity to foster mental health among adolescents, though future controlled studies are needed to more rigorously evaluate its efficacy.

Targeting teachers is relevant given the high prevalence of psychological distress in this group. Evidence shows that many teachers experience clinically significant symptoms such as anxiety and depression [20, 21], with mental health concerns increasing since the COVID-19 pandemic [23]. Similar trends have been observed among adolescents [1–5]. These data highlight the need for routine screening, early intervention, and stigma reduction within educational settings.

The psychological well-being of future teachers is an essential component of the educational system. Teachers’ mental health can influence the quality of instruction and the emotional climate experienced by adolescents [24–26]. Evidence indicates that distress during teacher training is associated with less favorable school environments, which may affect students’ academic performance and mental health [24]. Emotional overload—such as exhaustion from disruptive behaviors or lack of institutional support—has also been identified as a factor contributing to teacher burnout, limiting their ability to respond empathetically to students’ needs [40].

These findings highlight the magnitude of the mental health challenges faced by teachers and underscore the need for interventions that offer structured support, such as the Digital Vital House program. Educational settings offer a suitable context for these initiatives. In both teacher and adolescent training, there is growing recognition of the importance of fostering cognitive-emotional skills beyond curricular content, including resilience, emotional self-regulation, and emotional intelligence [13–15]. These competencies help teachers manage stress, reduce burnout risk, and create emotionally supportive learning environments. Current conceptual models emphasize skills that enable teachers to regulate their own emotions, recognize students’ emotions, and promote a positive classroom climate, which in turn supports students’ socio-emotional development [41–43].

Research indicates that teacher-focused interventions can reduce stress, anxiety, and burnout among educators [44] and improve classroom dynamics by strengthening teacher–student relationships and decreasing disruptive behaviors [41]. For students, these programs have been associated with increased prosocial behavior and reductions in externalizing symptoms and ADHD-related difficulties, suggesting their relevance for managing challenging situations [8]. Improvements in teachers’ well-being may also contribute to more supportive learning environments [24, 25]. The results obtained with the proposed intervention align with this evidence, particularly regarding the mental health of future teachers.

Improvements in several components of the ACT Hexaflex model after the “Vital House” intervention suggest increased psychological flexibility, a core construct in ACT. Strengthened processes included mindfulness, acceptance, values, cognitive defusion, and self-as-context, consistent with ACT principles. Psychological flexibility is associated with greater well-being and lower emotional rigidity, while inflexibility relates to anxiety and depression [33]. Interventions targeting these processes have shown benefits for emotional regulation and value-driven actions, including among teachers [18]. In educational contexts, strategies such as the symbolic rooms of Vital House may help future teachers accept internal experiences, maintain present-moment awareness, clarify values, and respond to self-critical thoughts with perspective. Overall, within the limitations previously noted, these findings indicate that digital introspective interventions may support psychological flexibility and provide teachers with skills to foster healthy classroom environments.

Unlike internal processes such as acceptance, cognitive defusion, or mindfulness—which can be meaningfully fostered through introspective practices and symbolic or experiential exercises such as those proposed in the “rooms of the Vital House”—committed action entails a qualitatively different level of intervention. Specifically, it requires bridging the gap between values clarification and overt behavior by translating personally meaningful values into concrete, observable, and sustained actions in daily life. The literature conceptualizes committed action as the most explicitly behavioral component of the psychological flexibility model, as it involves identifying valued directions, setting realistic and values-consistent goals, formulating action plans, and persistently engaging in these behaviors over time. This process necessarily involves the capacity to confront internal barriers such as discomfort, fear, and self‑doubt, as well as external obstacles including contextual constraints and lack of support, while maintaining behavioral coherence with one’s values [45, 46]. Therefore, while metaphorical and reflective exercises may effectively support awareness, clarification, and motivation, fostering committed action requires additional behavioral supports. This includes structured goal-setting, monitoring progress, and reinforcing persistence, ensuring that values are not only symbolically understood but also enacted through lived, sustainable patterns of behavior. Accordingly, while introspective and experiential interventions may lay the groundwork for value clarification, observable value-driven action is more likely to emerge over time, as it generally requires prolonged training, deliberate behavioral practice, and structured support mechanisms. Future research could extend the present approach by incorporating components specifically aimed at behavioral activation, such as structured goal-setting and action planning, in order to further strengthen the committed action dimension.

A notable finding is that the program enhanced introspection but did not significantly affect self-reflection, highlighting the distinct nature of these processes [47]. Introspection involves present-focused awareness of thoughts and emotions, whereas self-reflection requires retrospective analysis and advanced metacognitive skills. The intervention’s emphasis on mindful engagement rather than evaluative judgment aligns with this outcome. Importantly, the absence of increased self-reflection should not be viewed as a limitation, as excessive self-reflection can lead to rumination, self-criticism, and anxiety [48, 49]. In contrast, introspection supports emotional regulation and resilience without triggering dysfunctional thought patterns [50], offering a functional approach to teacher development.