As the prevalence of mental health issues continues to increase globally, more studies have focused on physical activity as a potential protective mediator for mental health disorders including anxiety and depression (Boone and Leadbeater, 2006; Schaal et al., 2011). Having extensively examined how exercise improves physical health, researchers are now focusing on the psychological impacts of physical activity (Eime et al., 2013; Nixdorf et al., 2016). Between 2-9% of children are diagnosed with major depressive disorder, while 5-10% of children and up to 25% of teenagers suffer from anxiety (Glover and Fritsch, 2018; Sabiston et al., 2016). Presenting adolescents with an opportunity to socialize, relieve stress, and build confidence, physical activity has been associated with decreased risk of these illnesses (Adachi and Willoughby, 2014; Boone and Leadbeater, 2006; Findlay and Bowker, 2009; Lubans et al., 2016; McMahon et al., 2017; Toseeb et al., 2014). Several studies suggest that physical activity is beneficial to the mental health of young people, 30-40% of whom will show moderate or severe depressive symptoms between ages 12 and 19 (Boone and Leadbeater, 2006; Sabiston et al., 2016). Strong et al. (2005) recommend school-age youth should engage in 60 minutes of exercise per day to increase muscle strength, reduce body fat, maintain healthy body weight, promote bone density, improve mood, and decrease symptoms of depression and anxiety. Therefore, individual and team sports seem to help mediate the presentation of psychological disorders and serve as effective treatment measures.
Furthermore, organized sports participation is associated with a decreased risk of anxiety, depression, feelings of hopelessness, suicidal ideation and suicide attempts, illicit drug use, and the smoking of tobacco products, above exercise alone (Miller et al., 2002; Miller and Hoffman, 2009; Pedersen et al., 2017). Organized sports correlate more positively with adolescent mental health than other forms of physical activity (Eime et al., 2013). Organized sports have been associated with decreased depressive symptoms, increased self-esteem, and improved social abilities (Sabiston et al., 2016; Vella et al., 2017). The social benefits of participating in sports have been linked to reduced stress and better self-reported overall mental health in young adults (Sabiston et al., 2016; Vella et al., 2017). A study from 2015 revealed that those who do not participate in or drop out of organized sports have greater social and emotional difficulties than those who continue to play (Vella et al., 2015). Non-athletes are also 10-20% more likely to suffer from mental health issues (Vella et al., 2017). The benefits of sport and physical activity on metrics of mental health have been well-established.
Not all sports, however, impact mental health in the same way. Kajbafnezhad et al. (2011) discovered "significant difference between [team sports and individual sports] in terms of psychological skills and motivation of athletic success" (p. 1904). Playing on a team both encourages fitness and allows young people to develop important mental and social skills (Boone and Leadbeater, 2006; Vella et al., 2017). Team sports provide an opportunity for children to learn to work well with others and effectively contribute to a group (Sabiston et al., 2016). The resulting sense of support and acceptance likely plays an integral role in reducing depressive symptoms and leads to healthy relationships with adults and peers (Eime et al., 2013; Boone and Lead-beater, 2006). Boone and Leadbeater (2006) found that positive experiences on teams with coaching, skill development, and peer support contribute to feelings of social acceptance and decreased body dissatisfaction and ultimately fewer depressive symptoms among adolescents.
Individual sports help cultivate other important psychological skills. When athletes practice alone, they can improve their ability to concentrate and improve mental strength. While individual sports often provide less social opportunity, they encourage responsibility and self-reliance. Individual sport athletes may engage in a "higher level of preparation" because their success depends completely on their own skills and training (Kajbafnezhad et al., 2011). Yet, this increased sense of accountability can lead to intense feelings of shame or guilt after losing (Nixdorf et al., 2016). Team sports are sometimes stressful as a result of competition, team dynamics or coaching issues, but individual sports may cause greater internal attribution such as shame after failure, which is linked to depressive symptoms (Boone and Leadbeater, 2006; Hanrahan and Cerin, 2009; Nixdorf et al., 2016). Nixdorf et al. (2016) reports that elite junior athletes who play individual sports suffer more from depression than those who play team sports. Sabiston et al. (2016) reveals that youth who engaged in team sports throughout high school reported fewer depressive symptoms later in life, but the same did not apply to individual sports. Both team and individual sports have been shown to support mental and physical health, but, as noted by Vella et al. (2017), "the weight of evidence suggests that participation in team sports may be more strongly linked to positive social and psychological outcomes when compared to individual sports" (p.688)
Individual sport athletes can exhibit increased anxiety not only because of the way they internalize failure, but also their tendency to set intense personal goals for themselves (Nixdorf et al., 2013). Individual sports for which judges determine success, including gymnastics, figure skating, and dance, correlate with the highest rates of anxiety in elite athletes; these athletes feel immense pressure to differentiate themselves from the competition in the pursuit of perfection and a judge's approval (Schaal et al., 2011). Team sport athletes also engage in perfectionist behaviors, but perhaps not to the extent of individual sport athletes (Nixdorf et al., 2013). The current study tests the hypothesis that team and individual sports have distinct associations with the diagnoses of anxiety and depression. In addition, we hypothesized that young team sport athletes are motivated to play for different reasons than individual sport athletes.
We conducted a cross-sectional study of athletes who underwent an injury prevention evaluation (IPE) at a sports injury prevention center affiliated with an academic pediatric medical center between April 2013 and February 2018. The focus of the center is to reduce the risk of sport-related injuries and conduct research on injury prevention in sport. Specifically, each athlete completes an extensive questionnaire detailing sports participation, previous injury history, training regimen, dietary intake, and sleeping habits followed by anatomic measurements, performance measures, biomechanical evaluations, functional movement assessments, and physical fitness screening. At the end of the evaluation a list of injuries for...