Suicide is a serious global public health problem, with 817,000 people terminating their lives each year (Naghavi, 2019; World Health Organization, 2021). The World Health Organization estimates that suicide is the fourth leading cause of death among people aged 15–29 years (World Health Organization, 2022), and more than 60,000 children and adolescents die each year as a result of suicide (Naghavi, 2019). Suicide rates are high among adolescents in Eastern and Central Europe, the high-income Asia-Pacific region, and the high-income North America region (Naghavi, 2019). Regarding gender differences, suicide rates are higher among males than females, except in the 15–19 age group (Naghavi, 2019). Despite the fact that suicide rates increase with age, it is the second most common cause of death among adolescents in Europe (Bilsen, 2018). While suicide is not even one of the top 10 common causes of death among older people. Previous studies indicated that age standardized mortality rates declined significantly between 1990 and 2016 in a significant number of countries, notably China, Denmark, and the Philippines (Naghavi, 2019). Although the suicide rate has declined significantly since 1990, as a result of successful public health actions, increases in the prevalence of suicide among adolescents has been observed in some regions due to the COVID-19 pandemic (Bersia et al., 2022; Goto et al., 2022).

In addition to death by suicide, suicidal ideation, suicide plans, and suicide attempts are modifiable suicide-related outcomes (O’Connor et al., 2013). Those suicide-related outcomes, especially among adolescents, is complex and results from the interaction of social, psychological, environmental and genetic risk factors (Wilcox et al., 2010). Suicidal ideation (or suicidal thoughts), which is defined as any thoughts about ending one’s own life, is considered the first step on the road to suicide (Kachur et al., 1995; Turecki et al., 2019). As suicidal ideation becomes more frequent and planned, the risk of taking actual suicidal action increases (Turecki et al., 2019). Suicide attempts, which is defined as an action of self-harm with the intention of presumed or actual death, may or may not result in death (Turecki et al., 2019). In the recent meta-analysis, the prevalence of suicidal ideation among 6- to 21-year-olds people varied by region, ranging from 14.3 to 22.6%, while the prevalence of suicide attempts ranged from 4.6 to 16.9% (van Meter et al., 2023). Another meta-analysis of 686,672 children and adolescents showed that the lifetime prevalence of suicidal ideation, plans, and attempts was 18.0, 9.9, and 6.0%, respectively (Lim et al., 2019). Given the complexity of suicide the actual number of deaths by suicide may be greatly underestimated due to unrecognized or misattributed (De Leo, 2015). Furthermore, the frequency of suicide-related outcomes is much higher, being estimated to be 10–20 times higher than the frequency of the death by suicide (Bilsen, 2018).

Suicide is not only an individual tragedy but also affects family, peers, and communities (Cerel et al., 2019). Furthermore, suicide and suicide-related outcomes can also be a heavy financial loss. It is estimated that suicide and suicide attempts cost the United States $58.4 billion each year (Shepard et al., 2016), and the average cost of suicide for adolescents in the most developed countries is more than $ 800,000 (Doran and Kinchin, 2020). In developing countries, the economic costs of suicide and suicide-related outcomes are even more severe, not only due to the associated medical burden, but also in terms of future lost productivity. Therefore, timely, evidence-based, and cost-effective interventions are required to address this global public health challenge (World Health Organization, 2021).

Previous research has identified genetic, biological, psychological, and social factors as risk factors for suicide in children and adolescents (Bilsen, 2018). While healthy lifestyle, such as sports participation, is identified to be protective factors for suicide and suicide-related outcomes among adolescents (Grasdalsmoen et al., 2020; Wasserman et al., 2021). This promising behavior is defined as purposeful active participation in sports related physical activities performed during leisure-time (Scheerder et al., 2005). Previous research showed that the prevalence of suicide-related outcomes was lower in high school and college students who participated in sports than those who did not (Lester, 1995; Brown and Blanton, 2002; Sabo et al., 2005; Brown et al., 2007; Babiss and Gangwisch, 2009; Taliaferro et al., 2011; Cho, 2014; Hu and Tang, 2022). Studies in the United States, Korea, and Canada reported that high school students who participated in school sports teams had lower odds of suicidal ideation (Dugas et al., 2012; Southerland et al., 2016; Park et al., 2020). Furthermore, among high school and college students in the United States, a lower incidence of suicide plans was found among those with higher sports participation compared to those with lower sports participation (Brown and Blanton, 2002; Sabo et al., 2005; Xiao et al., 2019). Meanwhile, participation in sports teams has also been reported to be protective factors for the suicide plans among secondary school students (Southerland et al., 2016). Previous studies suggested that sports participation is negatively associated with the incidence of suicide attempts among high school students (Brown and Blanton, 2002; Brown et al., 2007; Cho, 2014; Grasdalsmoen et al., 2020; Hu and Tang, 2022). Furthermore, suicide attempts were higher among high school and college students who did not participate in sports teams than among those who did (Southerland et al., 2016; Li et al., 2021).

Despite the fact that numerous studies have explored the association between sports participation and suicide-related outcomes in adolescent populations, there is no systematic review to summarize the extant evidence. Vancampfort et al. systematically reviewed the association between physical activity and suicidal ideation (Vancampfort et al., 2018a). However, Shull et al. considered sports participation is a subset of physical activity (Shull et al., 2020). Meanwhile, other research proposed that sports participation sometimes involves sedentary behavior and light physical activity (Leek et al., 2011; Guagliano et al., 2013). Therefore, a distinction needs to be performed between research on physical activity and sports participation. Although Zuckerman et al. systematically reviewed studies of team sports participation and suicidal ideation in young athletes, other suicide-related outcomes were ignored, and the participants were young athletes under the age of 25, the findings of these results are difficult to generalize to general adolescents (Zuckerman et al., 2021).

Accordingly, this systematic review aims to summarize and evaluate the association between sports participation and suicide-related outcomes in adolescents in observational studies and conduct gender subgroup analyses because of differences in suicide risk by gender.

This present systematic review was designed and conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline (Page et al., 2021). A systematic review protocol had been registered in the International Platform of Registered Systematic Review and Meta-Analysis Protocols (INPLASY202330072).

Systematically evaluating the association between sports participation and suicide-related outcomes among adolescents is considered of great public health significance because this information can inform interventions to reduce suicide-related behaviors in youth populations (Vancampfort et al., 2018a). To our knowledge, this present systematic review is one of the first studies to explore the association between sports participation and suicide-related outcomes in adolescents. While a large number of cross-sectional studies were included to determine this association, there was a lack of longitudinal studies examining the direction of the association between sports participation and suicide-related outcomes among adolescents. Based on good- to excellent-quality cross-sectional and longitudinal studies, the findings of this systematic review indicate evidence for a negative association between sports participation and suicidal ideation and suicide attempts among adolescents. However, it is currently unclear whether there is a consistent association between sports participation and suicide plans among adolescents. In gender-stratified subgroup analyses, it is uncertain whether the association between sports participation and suicidal ideation, suicide plans, and suicide attempts is consistent across males and females.

Previous systematic reviews and the current study differed in the population examined, the exposure variables, and outcome variables, thus drew inconsistent conclusions (Vancampfort et al., 2018a; Zuckerman et al., 2021). Our study finds that sports participation is negatively associated with suicidal ideation and suicide attempts. Zuckerman et al. reported that all three included studies supported that participation in team sports was associated with lower suicidal ideation (Zuckerman et al., 2021). However, Vancampfort et al. (2018a) study indicated that 7 of 14 studies in adolescent populations found a negative association between physical activity and suicidal ideation, but it was uncertain whether there was a consistent association. While the association between sports participation and suicide attempts among adolescents has not been reported in previous systematic reviews comprising observational studies. Fabiano et al. reported that more physical activity was associated with fewer suicide attempts in clinical populations (Fabiano et al., 2024). Evidence from randomized controlled trials also demonstrates that exercise reduces suicide attempts (Fabiano et al., 2023). However, it is currently unclear whether there is a consistent association between sports participation and suicide plans among adolescents. Meanwhile, no previous systematic review has provided evidence for this association.

A recent systematic review conducted by Vancampfort in 2018 examined physical activity and suicidal ideation across the lifespan, which included adolescents (Vancampfort et al., 2018a). Compared to this systematic review, our research specifically targeted the adolescent population and specifically examined sports participation rather than physical activity, and, more importantly, three suicide-related outcomes (suicidal ideation, suicide plans, and suicide attempts) rather than only suicidal ideation. The most recent systematic review assessed the behavioral, psychological, and social impact of team sports on young athletes (Zuckerman et al., 2021). While Zuckerman et al. also investigated cross-sectional and longitudinal associations between team sports and suicidal ideation, it targeted young athletes under the age of 25, not only general or school-attending. In the 2018 systematic review, Vancampfort et al. found an unclear association between physical activity participation and suicidal ideation among adolescents (Vancampfort et al., 2018a), which is inconsistent with our findings. One possible explanation is that systematic review only included studies up to May 2017, whereas our research included the five most up-to-date articles since 2018. Therefore, compared to the previous study, there is more evidence to support exploring the association between sports participation and suicidal ideation among adolescents.

The most recent systematic review found that participation in team sports was associated with lower suicidal ideation among young athletes under 25 years of age, which is in line with our findings (Zuckerman et al., 2021). However, Zuckerman et al. only investigated the association between team sports participation and suicidal ideation among young athletes, whereas our research extended the suicide-related outcomes to suicide plans and suicide attempts. More importantly, the population that Zuckerman’s study investigated was young athletes under the age of 25 years. Previous epidemiological evidence suggests that as the incidence of suicide-related outcomes increases with age, but suicide is a more common cause of death in younger age groups (Bilsen, 2018). Evidence from the previous systematic review can only support the association between team sports participation and suicidal ideation in young athletes, while the results of our research can support associations between sports participation and the three suicide-related outcomes in a broader population of adolescents, thus guiding the direction of subsequent research and supporting policy formulation.

While the present study provides more evidence to support the association between sports participation and suicide-related outcomes among adolescents compared to previous systematic reviews. Among the total sample, only suicidal ideation and suicide attempts met the current definition of being consistently related to sports participation among adolescents. However, it is noteworthy that inconsistencies between studies were reported in the association between sports participation and suicide plans, and in the gender-stratified analysis of the association between sports participation and all three suicide-related outcomes. In terms of suicide plans, only four studies investigated the relationship between sports participation and suicide plans, and the sample size was not sufficient to support consistent results. In both gender-stratified analyses of suicidal ideation and suicide attempts, there were sufficient sample sizes to support the evidence. Nevertheless, in all comparisons, while the majority of variables reported associations with sports participation, few were significant. Consequently, there is difficulty in drawing consistent conclusions about these variables. The lack of consistency in the results may be caused by differences in measurements and samples, and confounding or moderating variables may need to be considered in the analyses.

The first possible explanation is the bias introduced by measurement, as measuring physical activity or sports participation in adolescents is a challenging task. While we have very accurate but invasive measures (e.g., double-labeled water), to more user-friendly device-based measures (e.g., accelerometers), to self-reported measures (e.g., questionnaires), they are all prone to bias and limitations (Baranowski et al., 1993). All the studies included in this systematic review employed unvalidated self-report instruments to measure adolescent sports participation, which may result in fewer significant associations being reported. Moreover, compared to physical activity or sedentary behavior, sports participation is more complicated and harder to accurately assess.

The second explanation is the targeted sample. This systematic review included observational studies of various designs, which led to a very large variation in the sample size of included studies, ranging from 739 to 152,858. In adolescents, the expected moderate correlation between sample size and proportion of significant associations may explain the inconsistent results that emerge (Sallis et al., 2000). Furthermore, cohort differences may have contributed to the inconsistent results. Even when two studies adopt the same study design, recruit the same participants, and use the same measures, it is possible to achieve the different results. This is because different cohorts have different demographic characteristics, such as various socio-economic status, educational attainment, gender ratio, and ethnic distribution. Although all the studies included in this systematic review were from high-income countries, which reduces cohort differences to some extent, it is still not possible to conduct subgroup analyses based on ethnicity or socio-economic status. There may be different correlations between boys’ and girls’ sports participation, and this study conducted subgroup analyses according to gender, but was incapable of drawing consistent conclusions.

Although this systematic review could not induce the consistent association between sports participation and several suicide-related outcomes, it reported an association between higher sports participation and less suicidal ideation and suicide attempts. The physiological and psychological mechanisms of human suicide are unclear (O'Connor and Nock, 2014), and the mechanisms of how sports participation reduces suicidal ideation, suicide plans, and suicide attempts are also uncertain (Brown, 2005). Some hypothetical mechanisms may explain the negative association between sports participation and these three suicide-related outcomes. Suicidal behavior is a complex process that begins with the emergence of suicidal ideation, moves on to planning the method, place and time frame for suicide, to making the attempt, and may even end in suicide death (Dumon and Portzky, 2014). The main finding in this present study was that sports participation was negatively associated with suicidal ideation and suicide attempts, while the association between sports participation and suicide plans was unclear. In the Stress-Diathesis Model of Suicidal Behavior developed by van Heeringen, suicidal behavior is hypothesized to be the result of an interaction between proximal stressors and distal personal vulnerabilities or qualities (van Heeringen, 2012). Previous studies have suggested that a healthy lifestyle, including physical activity and sports participation, can reduce adolescents’ vulnerability to stress and thus reduce suicidal thoughts, suicide plans, and suicide attempts (Brown and Lawton, 1986). Furthermore, vigorous physical activity and social support may be potential mediating pathways by which sports participation is associated with a reduced risk of suicidal ideation. Taliaferro et al. proposed that vigorous physical activity mediated the association between sports participation and self-esteem and depression, and these two risk factors for suicidal ideation moderated the association between vigorous physical activity and suicidal ideation, while there is also a mediating role for social support in sports participation and risk factors for suicidal ideation (Taliaferro et al., 2010). Previous studies using accelerometer-based measurements support a higher level of vigorous physical activity in adolescent sports participants than in non-sport participants (Pfeiffer et al., 2006; Telford et al., 2016). Therefore, sports participation may enable adolescents to engage in more vigorous physical activity, and participation in vigorous physical activity is associated with better mental health (Hrafnkelsdottir et al., 2018; Wassenaar et al., 2021), which can reduce suicidal ideation in adolescents. Another potential mediating factor is social support. Previous research has suggested that adolescents who participate in sports can maintain positive social relationships with activity participants, such as teammates, organizers, coaches, and families (Brown and Blanton, 2002; Taliaferro et al., 2011; Eime et al., 2013), which can lead to greater interpersonal and social support. Among adolescents, higher social support is associated with higher well-being (Chu et al., 2010), reduced risk for depression and anxiety (Rueger et al., 2016; Qi et al., 2020). Consequently, among adolescents, sports participation leads to better social support from activity participants, and better social support leads to better mental health, thus lowering the risk of suicide-related outcomes. Furthermore, physiological perspectives can be used to reveal potential mechanisms for sports participation in suicide prevention. For example, exercise can reduce sensitivity to stress and peripheral effects that affect metabolic function (Tsatsoulis and Fountoulakis, 2006), thus preventing negative effects caused by stress, including suicide-related outcomes (Gerber and Pühse, 2009). Furthermore, exercise-induced increases in serum β-endorphin concentrations are associated with altered euphoria and nociception, which can influence the psychological profile of adolescents and therefore reduce the risk of suicide (Harber and Sutton, 1984).

This systematic review adds new evidence to support the association between higher level of sports participation and lower suicidal ideation and suicide attempts among adolescents. Whereas the association between sports participation and suicide plan is currently uncertain, and there is insufficient evidence to support differences between males and females.

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

MH: Conceptualization, Formal analysis, Investigation, Methodology, Writing – original draft, Writing – review & editing, Data curation, Project administration. ZY: Data curation, Formal analysis, Software, Writing – original draft, Writing – review & editing. LY: Conceptualization, Methodology, Project administration, Supervision, Writing – review & editing. SC: Formal analysis, Methodology, Writing – original draft, Writing – review & editing.