Direct and indirect effects of social support on youth physical activity behavior.

Social support (SS) from parents and peers are key reinforcing factors in the Youth Physical Activity Promotion (YPAP) model. This study aims to identify the relative contribution of parental and peer SS on youth participation in moderate to vigorous physical activity (MVPA). Participants included 203 high school students (n = 125 girls; mean age 14.99 ± 1.55 years). MVPA was assessed by accelerometry. SS influences were evaluated using a well-established scale. Structural equation modeling measured (AMOS, Version 19) the relative fit of the YPAP models using both parental and peer SS. Parental SS had significant associations with both predisposing factors, enjoyment (ß = .62, p < .01), and self-efficacy (ß= .32, p < .01), as well a direct effect on MVPA (ß = .30, p < .01). Peer SS had direct effect on MVPA (ß = .33, p < .05), also significantly influenced levels of enjoyment (ß = .47, p < .01) and self-efficacy (ß = .67, p < .01). In both models self-efficacy mediated the influence on MVPA. The direct effects for parents and peers were similar. This demonstrates that both parental and peer social support exert a strong influence on adolescent MVPA.

Early community contexts, race/ethnicity and young adult CVD risk factors: the protective role of education.

Using a sample of 13,500 adolescents (53% female and 47% male) who participated in all four waves of the National Longitudinal Study of Adolescent Health, this study used multilevel regression to examine the influence of early structural community adversity (as measured by rates of community poverty, single-parent headed families, and two indicators of employment) and racial/ethnic status on cardiovascular disease (CVD) risk factors of young adults (systolic blood pressure, diastolic blood pressure, and mean arterial pressure). The moderating role of youth's socioeconomic attainment was also examined. Results indicate that early community adversity and African American racial status place young adults at risk for CVD. Youth's socioeconomic attainment does not erase the persistent influences of early community adversity and African American racial status on CVD risk. However, the level of education attained can protect African American young adults and those experiencing early community adversity from CVD risk factors.

Heterogeneity in youth depressive symptom trajectories: social stratification and implications for young adult physical health.

PURPOSE: The first objective of this study was to investigate young adult physical health implications of adolescent depressive symptom trajectories. The second objective was to investigate the social stratification of adolescent depressive symptom trajectories. METHODS: Data came from the National Longitudinal Study of Adolescent Health. The analysis included the identification of depressive symptom trajectory groups. These four groups were then compared in terms of socioeconomic characteristics and change in physical health problems, from adolescence to young adulthood. RESULTS: Youth in the chronically high, increasing, and decreasing depressive symptoms groups showed significantly higher increases in physical health problems and poorer socioeconomic characteristics than did the consistently low group. CONCLUSIONS: The associations of adolescent depressive symptom trajectory groups with changes in physical health provide evidence for the etiological processes through which depression influences physical health. Differing socioeconomic characteristics of depressive symptom trajectory groups suggest social stratification of trajectories.