Adolescent Physical Activity, Mental Health, and Delinquency

Background: Modern teens are spending more time on technology and less time being physically active than ever before. The relationship between physical activity and wellbeing has been documented extensively in research, demonstrating that decreased physical activity can lead to poor mental health consequences. However, literature remains more limited on the adolescent population, who are at particular risk for negative outcomes such as poor mental health and criminal activity. Economic deprivation, a state in which one third of US adolescents live, further amplifies adolescent vulnerabilities. Therefore, the purpose of this study was to examine the relationships among physical activity, mental health, and delinquency among a large, nationally representative sample of economically deprived adolescents.

Methods: A secondary data analysis was conducted using a low socio-economic subsample (N=1486) of adolescents from the first wave of the 1994 National Longitudinal Survey of Adolescent to Adult Health (Add Health). The independent variable examined was level of physical activity in the past week, assessed using a scale created from three items on the survey for a total score ranging from 0 to 9. The dependent variables measured were mental health and delinquency. Mental health was measured using a scale created from 19 items on the survey assessing the adolescents’ feelings in the past week with total scores ranging from 0 to 57. Cronbach’s alpha for the mental health variable was .86. Frequency of delinquent behaviors in the past year was measured from 15 items on the survey with total scores ranging from 0 to 45. Cronbach’s alpha for the delinquency variable was .83. Multiple linear regression models were used to determine the direct effects between each of the variables. A Sobel test was used to determine the mediating effect of mental health on the relationship between physical activity and delinquency.

Results: Participants ranged in age from 11 to 19 years old. The majority of participants were female (53%) and white (49%). The average total household income in this sample was $28,440 (SD=46,500) and nearly half (45%) received food stamps. Most primary caregivers completed a high school level of education or less (57.3%). Average physical activity, mental health, and delinquency scores were 3.55 (SD=2.14), 44.46 (SD=8.13), and 4.45(SD=5.39) respectively. Multiple linear regression models indicated that physical activity significantly predicted higher mental health scores (b=0.40, p<.001) and higher levels of delinquency (b=0.30, p<.001). The Sobel test indicated a significant indirect effect (b=-0.06, p< .001) of physical activity on delinquency through mental health, indicating that mental health plays a mediating role in the relationship between physical activity and delinquency.

Conclusions and Implications: These results emphasize the important role of physical activity in the wellbeing of adolescents from economically deprived backgrounds. The implications from this study are particularly important in the aftermath of the COVID-19 pandemic, which negatively impacted activity levels. Future research should focus on examining physical activity as a targeted intervention to increase mental health, and implications from this study may provide a basis for supporting increased access to physical activity in schools and neighborhoods.