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Neurobiology
Depressive mood disorders distort and interfere with an individual’s ability to function. Research shows that both anxiety and depression can contribute to cognitive deficits. Studies have shown that physical activity can positively reduce the effects of depressive mood disorders. Depressive Disorder (DD) involves a complex set of structures that form the highly organized circuits involved in the control of emotions and reactions found to be hyperactive in stress response. Structural changes in the brain of the depressed individual are evident in the frontal cortex, frontal lobe, prefrontal orbital lobe, frontal corpus callosum, and the limbic system. Depressive symptoms harm performance on tasks requiring neural excitation, such as working memory maintenance. Various studies show that some form of physical activity has a significant positive effect on individuals experiencing depressive symptoms. Research has shown that the female adolescent pubertal stage, depressive symptoms experienced by the adolescent, and the level of physical activity are associated. Depression has alarmingly become a common mental health disorder experienced during the adolescent stage. A sedentary lifestyle, parental relationships, and menstrual irregularities can impact the mental health and self-concept of the adolescent female. There is a gap in investigating all three variables in one study to determine the proper intervention to help to provide relief for the female.
Previous Research
The focus was to determine the type of physical activity that provides the greatest differences between adolescents who are on both ends of the spectrum (highest/lowest) for risk of depressive symptoms. The 596 participants included 368 girls and 228 boys aged 15-19. The students who attended one of 16 Czech Republic secondary schools between 2015 and 2016 had the consent of their parents. The students wore the pedometers for the entire day except for swimming or bathing, from morning until bedtime. The research concluded that adolescents’ participation in school sports and structured physical activity can be protective against poor mental health and depressive symptoms. There were limitations to the study such as the inability to randomize the nationwide school and class section. Excessive administrative activities that disrupted the educational process and an inability to repeat the survey investigating Depressive symptoms, and well-being. The authors were also unable to distinguish between emotional, cognitive, and somatic levels of the depressive symptoms. They wanted to examine whether prospective reciprocal relations were stronger when major depressive diagnoses or depressive symptoms were found. The authors of this experiment wanted to shed light on two hypotheses:1. That physical activity reduces the risk for future onset of depression and 2. That it is also possible that depression results in a reduction in future physical activity.
The participants included 496 adolescent girls ages 11-15 years old. They were recruited from 4 public and 4 private middle schools located in a metropolitan city in the US. The girls completed a questionnaire, participated in structural interviews, and had their height and weight measured by a female research assistant yearly over the 6 years. Each participant received a $15 gift certificate. The Schedule for Affective Disorders and Schizophrenia for School-Age Children was used to assess whether the participants met the criteria for major depressive disorder. The girls identified the physical activity that they participated in more than 10 times over the year. Body mass index was calculated by dividing weight in kilograms by height in meters squared Baseline physical activity predicted fewer increases in depressive symptoms over time, the relative risk of later depression decreased by 1% for depressive symptoms, 8% for major or minor, and 16% for major depression. Girls who had major depression were 35% less likely to participate in one additional physical activity a year later and for those who had minor depression, 18% were less likely. An increase in depression correlated with a decrease in physical activity by 21%. Research indicates that regular physical activity offers some protective effect for the onset of major-minor depression in adolescent girls and that major-minor depression has an impact on the number of physical activities in which the adolescent female will participate. Based on the results it would be beneficial to use physical activity as a component of treatment and prevention. Hunter et al. (2016) examined how naturally occurring changes to school physical activity policy, recreational programming, public health resources, and the physical environment, impact adolescent MVPA over a 1-year period.
The authors believe that there is a gap in research as it pertains to the impact of changes that happen over time in school PA programs and how those changes affect the student. The authors believe that there is a gap in research as it pertains to the impact of changes that happen over time in school PA programs and how those changes affect the student. The results of the study revealed that some changes in recreational programming were associated with a significant change in student MVPA although there were no policy changes. The timing of data collection may have influenced results depending on the renovations that were completed. Factors such as student hunger, after-school transportation, and other student commitments could have impeded student participation in the activities influencing the results. Garn et al. (2020) examined the reciprocal effects model examining the interplay between adolescents’ physical self-concept and its facets and 7 days of objectively measured MVPA. The sample consisted of 1,767 adolescents 51% girls and 49% boys who attended 14 secondary schools in the Western Sydney area of the State of New South Wales, Australia. 62% identified as English Australian, 17% Asian, 12% Middle Eastern, 6% South Pacific, and 3% other. The average height and weight were 160 cm and kg, which translated to an average body mass index for the age of 22 and BMI-for-age z score of .70. Twenty-five percent of the sample could be classified as overweight or obese. The data was collected in the 1st and 4th term of year 8 and the 2nd term of year 9. The Physical Self-Inventory-Short Form (PSI-SF) measured global physical self-concept which included physical appearance, physical condition, physical strength, and sports competence. Accelerometers were used to measure MVPA for 7 days, 5 weekdays, and 2 weekends using 1-s epochs, and BMI was measured using a standard portable stadiometer and a digital scale.
The findings support hypothesis #1: MVPA positively predicted higher levels of physical self-concept, physical condition self-concept, sport competence self-concept, and strength self-concept, but did not support hypothesis #2: Global physical concept or any facet of the physical self-concept predicted future MVPA. Also, MVPA showed no longitudinal associations with future levels of physical attractiveness self-concept. The authors' research revealed that physical self-concept, physical condition self-concept, sport competence self-concept, and strength self-concept were the only outcomes of MVPA. By measuring MVPA with accelerometers rather than relying on self-reports, the study addressed what the authors considered to be a major gap in previous research on physical self-concept. MVPA has a positive effect on self-concept. The narrow demographic of white and female renders this study lacking in generalizability. The results made it unclear the significance of changing the environment or making PA accessible since some of the schools that made major improvements observed a significant decrease in MVPA. Potential confounding variables not accounted for such as student hunger, transportation, bike-ability of the neighborhood as well as the particular physical activity interests of the student body may not have been relatable.
The gap in research has been identified in the area of the positive association between cardiorespiratory fitness and reduced depressive symptoms in children and adolescents. Across 11 unique studies, 7095 children are included with a median age of 12.49, 53% female. A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) and the Meta-Analysis of Observational Studies in Epidemiology (MOOSE) statement. The meta-analysis revealed a weak inverse correlation between depressive symptoms and CRF. This observation highlights the potential role of promoting physical activity in children and adolescents finding it plausible that high CRF in children and adolescents may be protective against the development of depression. No direction of causality could be determined. Confounding factors, such as socio-economic status, were not accounted for and the generalization of the data is limited since most of the studies were conducted in the US, Europe, and Asia. The onset of puberty was not accounted for in these studies which could prove to be a confounding variable. Although the statistical significance was small the data collected could provide additional evidence that cardio health achieved through physical activity could potentially be positively associated with reduced depressive symptoms in children, adolescents, and adults.
Conclusion
Although there is significant evidence to support the implementation of physical activity ranging from a moderate to a vigorous level as a viable intervention for experiencing depressive symptoms, further research is warranted to address potential confounding variables. However, the results of this fictitious study and the reliability of the previous research demonstrate a need to pursue a physical activity as an intervention working in tandem with other approaches to help to address this important issue.
Article By: Michelle Way-Houser
June 2022
Department of Psychology, Liberty University
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