The Effects Of Physical Fitness On The Neuroticism-Depression Relationship

Abstract

Rates of depression begin to rise as children enter adolescence (Maughan et al., 2013). Individuals who score high on neuroticism, a fundamental personality trait, are more likely to exhibit depressed mood states and develop major depressive disorder (Saklofske et al., 1995). Conversely, physical fitness is negatively correlated with depression (Shomaker et al., 2012). Therefore, physical fitness may moderate the neuroticism-depression relationship. PURPOSE: To examine the separate moderation effects of physical fitness variables on the relationship between neuroticism and depression among adolescent boys and girls. METHODS: As part of their physical education classes, middle school students (829 boys, 880 girls; Mage = 12.23±0.96 years) completed the FITNESSGRAM® protocol (Plowman et al., 2013), including push-ups, curl-ups, aerobic capacity (i.e., 20 m shuttle run), and body composition (i.e., body mass index). Students were also asked to respond to survey items assessing personality traits (Neuroticism-Extraversion-Openness Personality Inventory; Costa et al., 1992) and depression (Center for Epidemiological Studies Depression Scale for Children; Faulstich et al., 1986). Four separate hierarchical regression analyses—one for each fitness variable—were conducted to determine each fitness variable’s moderation effect on the relationship between neuroticism and depression. RESULTS: The hierarchical regression analyses indicated that aerobic capacity and body composition had a moderation effect on the relationship between neuroticism and depression, R2 = .40, p < .001 and R2 = .40, p < .001, respectively. Subsequently, both the aerobic capacity-neuroticism interaction term and body composition-neuroticism interaction term were statistically significant, β = -.10, p < .001 and β = .05, p < .01, respectively. Moderation graphs supported that the aerobic capacity moderation effect was greater than the body composition moderation effect. CONCLUSIONS: The relationship between neuroticism and depression was weaker among those with either higher aerobic capacity or lower body composition. The findings indicate that certain physical fitness variables may help reduce the incidence rate of depression, neuroticism, and associated depressive symptomology.