The adolescent stage is a critical developmental period, marked by significant changes in physical, cognitive, and emotional functioning. In addition to these changes, there are many vulnerabilities during adolescence that can lead to the emergence of mental health disorders and bullying. The term “bullying” was used to define repeated aggressive behaviors intended to cause harm to others [1]. Adolescent mental health issues have been increasingly reported in recent years and are now considered a serious problem because so many adolescents develop mental health issues. There are several reasons why Social Emotional Learning (SEL) is becoming a viable method to help combat bullying and assist adolescents with their mental health. SEL is the process through which individuals develop and use the knowledge, attitudes, and skills necessary to understand and manage their emotions; set and achieve long-term and short-term goals; display empathy; establish and maintain healthy relationships; and make responsible decisions [2]. Research conducted by Durlak et al. [3] supports the notion that effective SEL programs increase the development of social-emotional skills and positive attitudes among adolescents and contribute to increased prosocial behavior and decreased behavioral and emotional problems.

SEL builds necessary skill sets for young people, including emotion regulation, empathy, making good choices, and developing healthy relationships. The programs developed support students' development of emotion regulation and empathy [4]. While SEL programs have been shown to have significant, immediate positive impacts on youth (such as improved school climate), some of these impacts (for example, reducing antisocial behaviors) appear to grow over time; therefore, they could be considered as having a “sleeper effect” [5]. Implementation of SEL within schools can assist in preventing behavioral problems in addition to enhancing adolescent mental health [6]. SEL initiatives educate students with the knowledge needed to manage stress, anxiety, and other negative emotions that greatly influence mental wellness [7]. Therefore, it is imperative that SEL programs be culturally adapted to meet the needs of each student's culture-specific values, norms, and life experiences. When SEL programs are not culturally adapted, students may be less likely to become engaged and/or motivated to participate in the program or to utilize the skills learned through the SEL program [8]. Additionally, the way in which students perceive their own level of social-emotional competency (or how socially emotionally competent they believe themselves to be) can be shaped by their culture. For example, students from Asian cultures typically place a high value on maintaining social order and controlling their emotions, while students from Western cultures place a greater value on expressing their emotions and valuing their individuality [9].

Research is increasingly demonstrating the positive impacts of SEL in reducing adolescent bullying behavior and promoting adolescent mental well-being. Research by Espelage et al. [10] reported that SEL-based intervention programs can significantly reduce both the prevalence of bully/victim behaviors. Taylor et al. [11] also reported that students who were exposed to SEL programs had lower symptoms of anxiety and depression. Domitrovich et al. [12], however, emphasized that high-quality, systemic delivery of SEL programs is required to maximize the effectiveness of SEL programs. Furthermore, research has identified attachment and emotion regulation as two key socio-emotional pathways through which adolescents respond to SEL program interventions. For example, research by Rossi et al. [13] identified that an individual's attachment style moderates the relationship between adverse childhood experiences and non-suicidal self-injury. In addition, the researchers reported that whether an individual experienced dissociative symptoms or post-traumatic stress disorder mediated the relationship was dependent upon the individual's primary attachment style. The results of this study provide evidence for the role of attachment as a mediator of socio-emotional adaptation in adolescents; therefore, SEL programs designed to enhance the development of emotional regulation and secure attachment may be beneficial in providing protection from negative mental health consequences associated with adolescent development. While significant advances have been made in developing SEL programs, there are still several unanswered questions about the long-term sustainability of SEL outcomes and the ability to be culturally responsive [14].

Although prior studies have frequently analyzed SEL's short-term impacts, SEL has rarely been studied for its longer-term effects as well as for its cross-cultural feasibility. Additionally, very few systematic reviews have analyzed how SEL can concurrently affect adolescent bullying prevention, emotional development, and overall mental health. Therefore, this systematic review will analyze all studies from 2013 through 2023 to determine the answers to the following three questions:

(1) How successful are SEL programs at reducing bullying among adolescents?

(2) How can SEL programs improve adolescents' emotional competence and overall mental health?

(3) What environmental and cultural factors support or detract from the use of SEL programs in school environments?

Based on an in-depth analysis of the articles included in this systematic review, key findings on the role of SEL in preventing bullying and improving adolescent mental well-being were identified and are presented in Table 1.

Table 2 categorizes the findings of the study on SEL's role in preventing bullying and improving adolescent mental well-being, mapping all 38 expert opinions into two main categories: Bullying Prevention and Mental Well-being Enhancement. These findings offer strong empirical support for the effectiveness of SEL in preventing bullying and improving adolescent mental well-being over the past decade. Table 3 details the development of SEL-related research by year.

The overall synthesis of 38 research studies examined how SEL is implemented and impacts various populations of students (adolescents) in a variety of educational settings and cultures. The general findings of this review support that SEL programmes are effective in reducing bullying behavior among adolescents as well as enhancing adolescents' mental health. Both quantitative and longitudinal studies found enhancements in empathy, peer cooperation, and adolescents' ability to regulate their emotions, while also supporting moderate to minor positive effects in students' social/emotional competencies and psychological health through the use of meta-analysis. Nonetheless, there are many variables that affect the quality of the evidence base for SEL. The majority of the studies reviewed focused on students in the West and East Asia, and very little research has been conducted in non-Western and/or conflict-affected areas. There was also considerable variability in methodology, in addition to many cross-sectional and short-term studies, which have limited long-term impact due to the fact that they did not include follow-up assessments. While the results are subject to limitations, the overwhelming body of evidence indicates that school-based SEL program implementation yields significant benefits for emotional resilience and school climate and ultimately demonstrates preventive potential in promoting student well-being and preventing bullying across settings.

A number of quantitative studies have provided additional support for the effectiveness of SEL interventions, as well as providing supporting longitudinal and meta-analytic data to inform the narrative synthesis described in this review. Multiple longitudinal and meta-analytic studies have shown SEL interventions are associated with minor to moderate positive changes in developmentally relevant outcomes. A meta-analysis by Olweus [1] reported that the correlation coefficient, r = 0.17, which links general aggression to bullying, is low, and a related meta-analysis indicated that the odds ratio (OR) for bullying perpetration as a predictor of later antisocial behavior is 2.06 (95% CI: 1.79–2.38), suggesting that SEL may help reduce long-term behavioral risk factors. A study conducted by Espelage et al. [10] indicated significant differences in the amount of bullying that occurred over time among students who participated in an SEL intervention compared to those who did not (δ = −0.20, 95% CI [−0.38, −0.03]), indicating that students who received SEL had fewer instances of bullying than their peers. Additionally, Taylor et al. [11] reported meta-analytically that SEL produces a statistically significant increase in SEL skills (ES = 0.17), positive attitudes toward self (ES = 0.17), academic performance (ES = 0.22), and decreases in emotional distress (ES = 0.12). The results from these studies suggest that SEL has benefits across both cognitive and emotional domains. Further, Nickerson et al. [16] found that SEL skills of students significantly mediated the relationship between SEL instruction and peer victimization (B = −0.14 for elementary/middle school; B = −0.09 for high school), highlighting SEL’s protective mechanisms. Van Ryzin et al. [18] found that SEL instruction produced significant intervention effects on bullying, victimization, and perceived stress, and decreased levels of emotional problems and increased levels of relatedness.

The evidence has demonstrated across numerous studies that SEL enhances social-emotional skills for youth and promotes prosocial behaviors while reducing bullying through improvements in students' emotional regulation, cooperation, and empathy. Many of the studies [1, 10, 16–18, 20] have shown that SEL-based programs are associated with a lower rate of victimization and aggression in many ways, including improving the relationship between peers as well as creating a more supportive classroom environment. The most effective programs to reduce bullying included cooperative learning and teacher fairness because they address both social and structural issues that cause bullying [18, 19]. In addition, long-term and school-wide SEL-based programs were more successful at reducing bullying over time and demonstrated that longer implementation of SEL-based programs, as well as more widespread implementation, would lead to sustained results [17, 44].

In addition to its prevention aspect, SEL is important for the development of adolescents' mental health. Research from numerous studies [11, 24–28] indicates that SEL strengthens social-emotional competence, reduces psychological distress, and fosters emotional resilience. These results were even more pronounced when SEL was used in high-stress or post-conflict areas [27], providing evidence of its adaptability to diverse psychosocial needs. The meta-analysis [11] also demonstrated significant improvements in emotional regulation and overall psychological health as a result of SEL programs, especially when those SEL programs had continued or school-wide implementation. Additionally, it was found that by combining with physical activity [25, 28], there are amplified positive outcomes, indicating that multi-dimensional programs that address both the emotional and physical aspects may have larger benefits.

Further shaping the effectiveness of SEL are culturally and contextually responsive adaptations. There is substantial evidence that programs developed to fit adolescents' cultural and ethnic identity produce better mental health outcomes and increase student engagement [14], which corresponds with transformational SEL and incorporates social and environmental justice to increase the emotional resilience of students and their feelings. In comparison, research conducted in the West has emphasized individual emotional regulation, empathy, and classroom climate, while research conducted in non-Western or collectivist cultures (such as Iran and Indonesia) has focused on community harmony, family unity, and the development of moral values as foundational to social-emotional growth. The importance of contextual responsiveness is significant because many of the high-quality studies on SEL were conducted in Western and East Asian contexts; therefore, there is a need for additional research and evidence based on diverse and underrepresented contexts. A second aspect that plays an important role in influencing the sustainability of SEL is the system level; specifically, teacher engagement and institutional support for SEL have been identified as critical to sustaining the positive effects of SEL [33, 34]. From a broader public health perspective, SEL's ability to contribute to emotional well-being and social cohesion supports arguments for incorporating it into broader national education and health policy and frameworks [36].

Evidence of SEL's applicability and universality is also emerging from a variety of sociocultural contexts outside of the Western and East Asian contexts. The use of culturally-sensitive SEL programming among Iranian adolescents was found by Mohammadi [29] to be effective in reducing their anxiety and depression, and Yang et al [43] identified improvements in engagement and emotional well-being among students from a variety of educational backgrounds. Gaber et al. [42] indicated that while the experience of migration may increase risk for adolescents’ mental health, it has been demonstrated that SEL can reduce such inequalities through improving adolescents' ability to regulate their emotions and develop social supports. The studies provide examples of how the focus and effectiveness of these programs are influenced by socioeconomic and cultural factors. Western SEL models typically operate within resource-rich, individualistic frameworks, whereas non-Western SEL models adapt SEL principles to collectivist, resource-poor environments where family and community play central roles in adolescents’ lives. Such findings indicate that, if implemented in ways that are sensitive to the local culture, SEL could serve as a framework for enhancing the inclusion and equity of addressing mental health inequities and promoting psychosocial well-being among a wide range of populations.

Adolescents who participate in SEL initiatives have been shown to maintain improved levels of emotional control, social competence, and psychological wellness as a result of their SEL experience. Longitudinal and experimental studies conducted in high-quality research, such as those by Taylor et al. [11] and Agley et al. [24], demonstrated that SEL participation positively impacted adolescents' emotional regulation, social competence, and overall psychological health. The ability of SEL to be implemented across a variety of stressful environments has been demonstrated through evidence from conflict-affected environments [27] and through evidence that included an integrated physical activity component [25]. In addition to enhancing students' emotional health, well-implemented, whole school SEL programs have also created positive peer interactions and supportive learning climates [36]. These factors are interdependent; as indicated by Corcoran et al. [34], the SEL-related gains may enhance students' ability to engage and perform academically, due to their development of essential interpersonal skills.

Over the last ten years, SEL implementation has evolved from primarily a classroom activity to a systems-wide approach. Murano et al. [31] reported that there has been an increasing amount of research focused on the growth of early childhood SEL, with significant gains for the social/emotional development of preschoolers. Wigelsworth et al. [32] stated that a successful program is highly dependent on the level of engagement of developers and the degree to which the program can be adapted to fit the context in which it is being implemented. Additionally, there is an increasing interest in addressing teacher wellness and a growing body of research demonstrating strong links between SEL and student academic achievement [33, 34]. Although there have been many positive changes in how SEL is implemented, the challenges to sustainable implementation remain very real. Challenges include teacher preparation, resources, and the lack of systemic integration of SEL, as stated by Oberle et al. [37] and Lawson et al. [39]. Kennedy [38] added that SEL must be embedded in a framework of compassion and diversity-centered leadership to ensure that SEL is inclusive and will have lasting effects. To address these challenges, we need greater institutional commitment to supporting SEL as well as policies that provide the necessary support to take evidence-based SEL models and make them scalable and equitable in educational practice.

Research into the future of SEL should extend on the results of this study to help address both methodological and contextually relevant issues found in the current body of literature. Specifically, Domitrovich et al. [12] reported a need to examine in greater detail social-emotional competency as a primary mediator in adolescents' development; similarly, Schonert-Reichl [33] suggested that, although teachers are involved in SEL programs, teacher participation has been significantly under-investigated as a factor in determining the success or failure of SEL programs. Greenberg et al. [36] also called for longitudinal, systemic assessments to investigate how SEL affects larger educational and health-related outcomes over time. Taylor et al. [11] stated that consistent follow-up research would be necessary to determine if SEL maintains positive effects after an intervention period has ended and across multiple stages of developmental growth.

The importance of SEL in promoting the well-being of adolescents, in preventing bullying, and in developing their social-emotional competencies is highlighted in this study. The results of the study indicate that the programs based on SEL create a safer, more supportive, and more inclusive school community for students; they also enhance the positive relations between peers and reduce victimization among adolescents. In addition, research indicates that SEL has a positive impact on the mental health of adolescents when implemented in conjunction with culturally responsive practices and through the support of school-based implementation.

While there are many documented positive effects of SEL, there are still many barriers to widespread and sustainable implementation of it in schools, including teacher preparation/training, resource availability/ allocation, and culturally adapting to meet the needs of the local school community. SEL can achieve long-term viability in the educational system through being an integral part of the public education policy and adequately funded through continuous professional training for teachers on how to teach SEL, through school administrative actions that provide for a systematic assessment of the efficacy of SEL, and through collaboration among educators, families, and other local community-based organizations to promote a culture of SEL throughout schools rather than as a short-term “program.”

Future research is needed to assess the lasting impact of SEL programs, extending into the post-educational arena (emotional resiliency, academic achievement, etc.), as well as how educators contribute to adopting SEL and whether culturally based models are successful.

Ultimately, SEL represents a viable method of developing students' emotional intelligence, decreasing behavioral problems, and creating a more complete, emotionally intelligent learner. By adopting a cohesive policy for implementing SEL and by working together as a team, schools can produce resilient, compassionate, and socially competent learners who create a positive learning environment that is inclusive and supportive.