1. Introduction

The world is currently facing a very challenging public health problem: the significant prevalence of mental health problems in the general population and adolescents and young people ^[1][2], as well as their low/moderate levels of mental health literacy ^[3][4][5].

The literature so far shows us that the levels of mental health literacy (MHL) of the general population and adolescents have been progressively increasing but are still at low/moderate levels ^[3][4][5]. This contributes to the absence of help seeking by adolescents, affects their development and increases the risk of psychiatric disorders recurring ^[6][7][8].

In this rentryview, we adopted the WHO definition of mental health ^[9], which conceptualizes it as something more than the absence of disease; rather, it considers that it “is a state of well-being in which an individual realizes his or her own abilities, can cope with the normal stresses of life, can work productively and is able to make a contribution to his or her community” (p. 38). Another concept that is important to define is mental disorders, which encompasses several mental problems “generally characterized by some combination of abnormal thoughts, emotions, behaviour and relationships with others” ^[9] (p. 38). Regarding stigma, in this rentryview, it is understood as “a mark of shame, disgrace or disapproval which results in an individual being rejected, discriminated against, and excluded from participating in a number of different areas of society” ^[10] (p. 18). We consider that the concept of help seeking “is an adaptive coping process that is the attempt to obtain external assistance to deal with a mental health concern” ^[11] (p. 180), including formal (health professionals, etc.) or informal sources (friends, family, etc.), encompassing not only the self-help strategies but also the first aid skills to support others ^[12]. It is also important to clarify that in this rentryview, the authors consider that knowledge on achieving/maintaining good mental health comprises how to prevent mental disorders and promote mental health, such as having stable friendships and family support, to sleep enough, practice exercise, think in a positive way, avoid substance abuse, to have meaningful and enjoyable activities and relax ^[12]. According to the World Health Organization ^[13], adolescence encompasses all individuals aged between 10 and 19 years. It is the period in the life cycle between childhood and adulthood, characterised by profound physical and mental changes, during which attitudes develop and can still be changed ^[14][15]. Therefore, adolescence is considered a crucial period of opportunity to promote mental health ^[9]. Better literacy at a young age has a direct and positive impact on adult life. It enables adolescents to acquire the knowledge and define the attitudes and behaviours that will accompany them in their future lives ^[16][17]. Specifically, it gives adolescents the ability to positively manage their thoughts and emotions to build healthy social and family relationships, all based on a strong, positive sense of identity. Therefore, without a good level of MHL, adolescents will not develop healthily as they grow to adulthood ^[16][18], because without the knowledge and skills necessary to prevent the onset of mental disorders and to promote good mental health, these disorders are more likely to set in during adolescence and perpetuate themselves chronically. For this reason, adolescents are a primary target population for the promotion of MHL.

The World Health Organization  ^[9] defined in its Mental Health Action Plan 2013–2020 that one of the objectives to attain at a global level is to implement strategies for the promotion and prevention of mental health problems, highlighting the importance of intervening not only on the needs of people with defined mental disorders but also on the protection and promotion of the mental health of all citizens. One such strategy is mental health literacy.

2. Search Strategy

In this rentryview, we searched the electronic scientific databases MEDLINE, CINAHL

Plus with Full Text, SciELO, and SCOPUS, using the Boolean phrase : (adolescent* AND ‘mental health’ AND (literacy OR ‘health literacy’ OR ‘mental health literacy’) AND (program* OR course* OR intervention*) AND promotion AND school*), retrospectively from 1 January 2013 to 31 July 2020. In the electronic repositories OpenGrey (a European repository) and RCAAP (the Open Access Scientific Repository of Portugal), the search was carried out using a shorter Boolean phrase: adolescent* AND ‘mental health’ AND school*, using the same period, and MESH and DECS (Descriptors in Health Science) terms as descriptors. The search in both databases and repositories was conducted in December 2019 and updated in August 2020. The reference lists of all articles included were also analysed, and additional relevant articles were identified and included in this scoping rentryview. A total of 29 articles were included.

3. Analysis on Results

Of the 29 articles included, twelve were experimental studies (of which two were study protocols and two were pilot studies), nine were quasi-experimental studies (two of which were pilot studies), three were descriptive articles, two were secondary analyses, two were systematic reviews of the literature and one was a mixed study (pilot study).

Eight articles addressed knowledge on how to obtain/maintain good mental

health: two were experimental studies ^[19][20][32,33], two were quasi-experimental ^[21][22][34,35], two were descriptive articles ^[23][24][36,37] and two were secondary analyses ^[25][26][38,39].

Twenty-four articles addressed programmes/interventions that aim to promote knowledge about mental disorders and their treatments, of which ten were experimental studies ^{[19][20][2721][2822][2923][3024][3125][3226][3327][3428]}, seven were quasi-experimental studies ^{[2129][2230][3531][3632][3733][3834][3935]}, three were descriptive articles ^{[2336][2437][4038]}, two were secondary analyses ^[2539][2640], one was a mixed study ^[15] and one was a systematic literature review ^[41].

Of the 24 articles that address programs/interventions whose objective is to reduce the stigma, ten were experimental studies ^{[19][20][2923][3024][3125][3226][3327][3428][42][43]}, six were quasi-experimental ^{[2230][3531][3632][3733][44][45]}, three were descriptive articles ^{[2336][2437][4038]}, two were secondary analyses ^[2539][2640], two were systematic reviews of the literature ^[41][46] and one is a mixed study ^[15].

Fifteen articles addressed programmes/interventions that aimed to promote help-seeking, of which seven were experimental studies ^{[19][2721][2822][3024][3125][3327][3428]}, five were quasi-experimental studies ^{[2230][3531][3733][3834][3935]}, one was a descriptive article ^[4038], one was a mixed study ^[15] and one was a systematic literature review ^[41].

4. Current Insights

One of the objectives of this rentryview was to discriminate the characteristics of programmes/interventions that promote MHL among adolescents. Most programmes/interventions targeted adolescents aged ≤14 years, thus making an important contribution to preventing the onset of mental health problems at an early age ^[13].

About half of the programmes/interventions were taught by the adolescents’ regular teachers. The rest used staff from outside the school, with only a few being taught by health professionals. These results highlight the need for greater intervention from health professionals, particularly those in primary health care and specifically nurses, who play a decisive role in the community’s health ^[5]. 

In terms of the strategies used, the results show the use of expositive, demonstrative, participative methodologies based on contact (direct or indirect) and/or the supply of information material. These strategies were used in isolation or as complements. 

The variability of the duration of the programmes/interventions analysed indicates that they may be flexible in terms of time, even though a significant proportion of the

analysed programmes/interventions state that the fact that they are of short duration is an advantage because they save resources.

None of the reviewed studies used instruments to assess outcomes concerning knowledge about achieving and maintaining good mental health, which is in line with the findings of Wei et al. ^[47][9].

Another objective was to know in which settings/contexts these programmes/interventions were carried out. Most of the programmes/interventions were implemented in a classroom environment. This fact demonstrates the importance of the school setting in promoting the MHL of adolescents and is in line with the research reported in this area ^[18][17]. It is also important to mention that the most programmes included in this scoping review consist of face to face interventions, only two programmes encompass online interventions (“EspaiJove.net” e “The Guide and MyHealth Magazine”)  ^[19][2336] and only one compares the same programme in its face to face version with the online version (“StresSOS”) ^[2822]. Both “EspaiJove.net” ^[19] and the “StresSOS” ^[2822] programmes do not have results yet because they are study protocols, but “The Guide and MyHealth Magazine”  ^[2336] already has results and they indicate improvements in the adolescents’ MHL when combining face to face and online interventions. However, we believe that in the future, more studies will be needed to compare both interventions and gather more evidence.

Finally, the last objective was to know the barriers and facilitators to the implementation of these programmes/interventions. The results obtained indicate that the main barriers to implementing the programmes/interventions are the difficulty of coordination with the various school stakeholders, the interruption of school curricula and the lack of incentives for participants. The main facilitators were the programmes/interventions being part of the school curriculum, not depending on resources outside the school and using interactive methodologies. These aspects should be considered when implementing future interventions so as not to compromise their effectiveness.

5. Conclusions

The results of this revientryw allow us to identify programmes/interventions that promote the MHL of adolescents, as well as to provide clues about some of the characteristics that such programmes/interventions should have, about some of the barriers and facilitators to their implementation and, finally, about the gaps found in this research area.

Although most of the analysed studies have apparently shown positive results in promoting the MHL of adolescents in school settings, these results are difficult to interpret and compare due to the lack of use of validated instruments and the great variability of the assessment instruments used.

Future research should be conducted to harmonise programmes/interventions that aim to promote each of the components of MHL, and MHL holistically in the adolescent population. To this end, further experimental or quasi-experimental studies should be carried out to obtain the best possible evidence, using validated assessment tools and including follow-up periods. Interventions should focus on adolescents aged ≤14 years; could be of short duration if the aim is to increase knowledge or help seeking, or of longer duration if the objective is to intervene at the level of adolescents’ attitudes/stigma; may include ‘booster’ sessions to reinforce and maintain the levels of MHL; should take place in the classroom; use complementary expository and interactive strategies; and have a more active intervention from health professionals.

We should focus on the implementation or construction of programmes/interventions that promote knowledge on how to obtain/ maintain good mental health and the use or construction of instruments that assess this component of MHL, whose importance is currently being increasingly recognised by research.