Volume 50 | Number 5 | October 2015

Abstract List

Jun Zhang M.S., Steven T. Yen Ph.D.


Objective

To investigate the roles of physical activity (exercise) and sociodemographic factors in depressive symptoms among men and women in the United States.


Data Source

2011 U.S. Behavioral Risk Factor Surveillance System ().


Study Design

Patient Health Questionnaire Depression Scale (‐8) scores are aggregated and divided into five categories. An ordered switching probability model with binary endogenous physical activity is developed to accommodate ordinality of depression categories and ameliorate statistical biases due to endogeneity of physical activity.


Principal Findings

Average treatment effects suggest physical activity ameliorates depressive symptoms among mildly and moderately depressed individuals, most notably among mildly depressed women. Gender differences exist in the roles of sociodemographic factors, with age, income, race, education, employment status, and recent mental health condition playing differentiated roles in affecting depressive symptoms.


Conclusions

Regular physical activity reduces depressive symptoms among both men and women with mild to moderate depression, notably among women.