The students and their teachers' daily interaction has an incommensurable power: they can establish a relationship between teacher and students that could play a vital role in the students’ mental health development. These last decades, researchers have been studying how this bond could affect students' lives, not only in their learnings but expanding the studied effects to children's development in other areas (Sabol & Pianta, 2012).

Sabol and Pianta (2012) have studied different approaches used to analyze the relation teacher-student. The developmental systems theory proposes educational actors as different elements that are interrelated in proximity and impact each other: the children would be part of a dynamic group of systems, which allows the interaction with other components of these systems. These interactions influence children on different levels, depending on their proximity. Therefore, teachers and children would impact each other due to the proximal level, and through the daily relation, they develop at the school (Pianta, Hamre & Stuhlman, 2003).

Last research tendencies on teacher-student relationship have included in their frames the attachment theory approach (Spilt, Koomen, Thijs & van der Leij, 2012; Sabol & Pianta, 2012), originally orientated to the study of the relation between children and their parents or, otherwise, their principal caregivers. This could be an example of the relevance that the teacher-student relationship is gaining in the educational field. Following this tendency, Howes (2001) analyzed the relation teacher-student based on two theories: an adapted version of the attachment to teacher-student relationship and the social contextual theory, founding that, even when coming from a non-secure attachment relationship with their parents, students could build a secure attachment with teachers at early years (Howes, 2001, p.193).

With the constant interaction in the educational environment, teachers can even take the “significant other” role to their students (Morris, 2015). This relation could become even tighter when the students are in the middle of problems that concern their families, especially neglecting parents: students could search for support in alternative actors (Leavey, Rothi & Paul, 2010).

One of the necessary consequences of establishing this positive relationship between the teacher and the student is its impact on students' mental well-being. Some authors state that this relation directly impacts a student's mental health when support is its main characteristic (Hamre & Pianta, 2001). This "new attachment" provided by the teacher could offer other profits connected to improving the learning process and outcomes of children and their social skills, peer relationships, and even in the improvement of disrupting performances (Pianta & Stuhlman, 2004). Other positive effects of this bond could be a decline in students' levels of aggressivity (Hughes et al., 2000). The relationship as a protector factor to children in challenging environments, showing promising results in research involving aggressive surroundings, neglecting parents, and racial discrimination, among other issues (Meehan, Hughes & Cavell, 2003; Sabol & Pianta, 2012).

Traditionally, the teachers’ role has been the “delivery” of content to students about different disciplines that can improve their academic skills regarding their entrance to the work system. Lately, the practice has been introduced in schools to reinforce learnings in a combination of theory and practice. To Morris (2015), the teaching of mental well-being practices in schools should have a similar process:

we should be teaching the students how to be well, how to do well-being (…) we have to get the students to experience it. When teaching about the benefits of exercise, teachers have to get the students to exercise to see those benefits for themselves. Suppose someone is teaching cognitive skills (such as those on resilience). In that case, the teacher has to get the students practicing them and applying them in real-life situations: it is no good just talking about it or handing over a worksheet (p. 14).

In schools, creating spaces and practices to enhance students' well-being is one of the crucial functions of teachers, doing collaborative work with the school community's planning to aboard this subject (Wyn et al., 2000). Thus, promoting students' mental well-being in the classroom would be related to creating and maintaining a positive classroom climate.

In this kind of support from the teacher, the community's spirit can be reflected because creating a climate that promotes mental well-being in students is done at a group level (Mælan et al., 2018).

A research carried out in Norway by Mælan, Tjomsland, Samdal & Thruston (2020) revealed that teacher practices aiming to promote mental well-being in the classroom caused students' positive feelings and perceptions. It included a sense of belonging, actions that made them feel supported emotionally, and the possibility of strengthening bonds between classmates.

Among all the new possibilities that open with the new perspective proposed, “The use of schools as a platform for increasing awareness, facilitating early detection and referring cases to mental health care has been highlighted as a promising alternative" (Vieira et al., 2014, p.2).

In the United Kingdom, GP surgery was historically the first place to consult about mental health, specifically diagnosing a possible clinical depression (Maag, Rutheford & Parks,1988). As an “everyday” figure in children’s lives, and as an essential part of the educational community, teachers nowadays have a platform to observe the changes that students could present as symptoms that something is not going well with them concerning mental well-being, among other dimensions.

Teachers could be among the first persons in hearing the alarm call of students with problems affecting their well-being and even identify some of the signals they send, and that sometimes could be ignored at home (House of Commons, 2017). For Vieira et al. (2014), this could happen because schools are one of the principal places where students could express their struggles related to their mental health state, and this makes teachers privileged witnesses due to their contact in the classroom.

Unruly behavior in the classroom climate, problems in the social sphere between students with mental health problems and their peers, and difficulties or radical changes in their academic outcomes may indicate issues in the students' mental well-being (Rothi et al., 2008).

The quotidian coexistence could, as an example, allow teachers to recognize signals of mental health issues as depression due to symptoms that could be shown in the educational environment and that could be attributed to characteristics related to changes appearing during the teenage years (Puura, Almqvist, Phia, Moilanen, Tamminen, Kumpulainen, Räsänen & Koivisto, 2003).

Due to the relationship that teachers can establish with parents through their children's education, parents also see teachers as a resource to look for support or advice when they have doubts about their children's mental well-being (House of Commons, 2017).

Thus, the teachers' role is crucial as the first door of the students identifying specific symptoms to receive professional attention in the mental health sphere. They can prevent students' exposition to dangerous situations or support them in getting help to prevent a possible mental breakdown.

With the premise of Weist (2003) of schools as communities inside more prominent communities, the contact of schools and organizations or professionals working in mental health intervention allows teachers to become a bridge between educational and health institutions. With this, the visualization of mental health problems gains ground to issues related directly to academic performance issues:

there is evidence that youth presenting “internalizing” disorders such as depression, anxiety and trauma, interpersonal issues, and developmental problems may be referred for services less often. In contrast, students showing acting-out behaviors, attention deficit hyperactivity disorder, or obvious academic problems are more likely to be referred (Splett et al., 2013, p.250).

Therefore, to Vieira et al. (2014), it is essential to enhance teachers’ skills to help them identify between their students whose mental well-being could be presenting difficulties and generate the community's links for a practical intervention with mental health professionals.

This third proposal for the teachers’ role might be the most polemic of all those presented due to the reluctance of professionals in the educational ground to “label” students as they recognize themselves as education and not mental health professionals. Teachers may lack the competencies to point to the key of the problem the student could be presenting. Besides, other teachers could be against including mental health issues between their tasks (Morris, 2015). However, this proposition does not intend to transform teachers into mental health professionals, but tools that help them catch some clues about their students’ well-being.

Some authors also mention teachers' bias in making referrals alluding to mental health problems focusing only on their worries about children's academic outcomes (Vieira et al., 2014), without paying attention to other spheres that could typically be functioning. This could lead to extreme outsourcing of responsibility when connecting the causes of the students' failures to inexistent difficulties related to their mental well-being.

Finally, even considering the importance of teachers' participation in detecting students with struggles related to mental well-being, another reason to oppose this new function could be associated with the possible failures in the implementation of strategies in the classroom. They are related to the lack of teachers' domain when talking about mental well-being and mental health (Severson, 2007).

There is no doubt about the importance of the role of teachers related to students’ mental health. Nevertheless, it is essential to take this issue seriously when we talk about our students. So, it would be crucial to open the question: are teachers prepared to attend situations related to their students’ mental health issues?

For the House of Commons, an ideal school would be that one where mental well-being was supported and immerse “throughout the culture of the school and curriculum as well as in staff training and continuing professional development” (House of Commons, 2017, p. 3). This process could enhance the changes perceived in children and young people’s mental well-being. Teachers are essential to agency change in children because classrooms allow intervening risk or actual situations. Therefore, the training to carry out this labor is essential (Sabol & Pianta, 2012, p. 222). According to Graham, Phelps, Maddison & Firzgerald (2011), “Whilst teachers are now expected to be responsive to a wide range of student needs and circumstances, they receive little in their pre-service and subsequent teacher education to adequately prepare them for such realities” (p. 479).

During the implementation of the program "Health Promotion Schools," the World Health Organization found insufficient policies and budgets and school personnel with low skills and knowledge about mental health between the principal obstacles inside schools to enhance students' mental well-being rates (World Health Organization, 2018). Other authors also present a lack of knowledge in mental well-being in professionals working in education, especially in teachers (Weist, 2003; Feinstein, 2015).

The value of teachers' training in mental well-being goes beyond the importance of their role in education and the perception of authorities and other institutions about their competencies. Their value is also connected to their own skills' perception. Atkinson and Hornby (2002) found that teachers felt a lack of confidence in their skills when coping with situations related to their students' mental well-being.

Following the idea mentioned above of schools immerse in communities, teachers' training in mental health aspects could help them make better and more accurate descriptions of their students and their circumstances when in need of attention in specialized mental health institutions. This could enhance the work alliance between different institutions working to benefit children and young people (Feinstein, 2015). To the House of Commons, "Strong partnerships between the education sector and mental health services improve the provision for children's mental health and well-being" (House of Commons, 2017, p. 3).

Another possible effect that training could have on communities and teachers is their approach to students who struggle with mental health issues. Weist (2003) explains that the mental health field has been traditionally focused on psychopathologic regard to children's issues. Nonetheless, the formation of teachers in this area, if well-executed, could make a move from this emphasis and help teachers to enhance his work into the promotion of mental well-being in students, without ignoring the knowledge of children's psychology to act successfully when in need of detection of any problem.

In an experiment carried out by Bostock and Kitt (2011), the authors found that teachers, in their Postgraduate Certificate in Education (PGCE), were more motivated to receive formation and include mental health practices well-being for students than more experimented teachers. This could be related to the novelty of incorporating the subject in education, which gives the new generations a better acceptance of different role functions due to its advantages.

After the experience of delivering a workshop for teachers about depression in children and adolescents, Moor et al. (2007) found that teachers were more comfortable and self-assured when they had to cope with students battling with clinical depression. According to Weist (2003), the possibility to know more in deep the emotional needs and how to support them could change their tolerance and comprehension of this kind of issue between students.

Due to the benefits that this knowledge could bring to professionals in the educational field, many authors present ideas about how teachers' training should be carried out. For Feinstein (2015), the development of skills connected to mental health and well-being should be incorporated in the initial training curriculum. Since teachers daily work with children and adolescents, it seems urgent to place mental health and well-being as a permanent subject of teachers' training instead of an alternative to develop in their careers.

The institution mentioned above also considers the importance of continuous training in this field for teachers during their active years, idea is also supported by Bostock et al. (2011). They believe that postgraduate formation is crucial, especially for teachers with a lack of experience. Without a doubt, they will find cases that require this kind of knowledge during their functions in schools.

Anyhow, considering schools as communities, the reinforcement of school-based professionals' skills like teachers should be incorporated to improve students' mental health. For Weist (2003), “there is a clear need for interdisciplinary efforts that alter paradigms to focus more on environmental factors, enhancing strengths and promoting mental health in natural environments such as schools” (Weist, 2003, p. 80).

Even when, in general, the importance of mental well-being has received a positive response from the education field, it is still possible to find barriers in the path to their full introduction in educational communities.

Weist (2003) explains that one of the difficulties that teachers’ training could find could be the lack of resources that schools have in general. Also, the absence of time in schools could be a barrier, especially between teachers, to attend to this kind of formation due to the many accomplishments that they must reach (Weist 2003; Rothi et al., 2008). Those factors, among others, could trigger negative feelings in teachers. The mix of aspects could contemplate time, overloading of responsibilities, the skills they should acquire to cope with new subjects as mental health, and the resources schools offer to these professionals to undertake this new function (Ekornes, 2017).

According to Rothi et al. (2008), resistance could be present between some teachers because they could feel that this kind of formation would install blurred lines between the core of their schools' functions and those belonging to mental health professionals.

As a relief from the situation above, Weist (2003) mentions mental health professionals' assistance in schools that could assist teachers in students' attention, instead of training them, which would add more responsibilities and tasks to their quotidian. This way could be an alternative to teachers who show some opposition to receive systematic mental health training.

Even with the assumption of teachers' positive attitude to the introduction of mental well-being subjects in their jobs, other problems could interfere in the implementation. The priority of cognitive and academic skills and contents concerning classroom time can also affect teachers' perception and the action of getting involved and trained in mental health. Some teachers may perceive that time spent in mental health activities could be used in the traditionally more important subjects to the curriculum and have a more significant impact on the evaluation of their work (Ekornes, 2017).

Finally, another factor that must be considered a possible barrier is the institutional culture, traduced as difficult for authorities to adopt a whole-school approach when thinking about enhancing their students’ mental health (Dumond & Istance, 2010). This obstacle would be significant when recalling the idea of a mental health improvement supported by the whole community instead of isolated interventions.