Longitudinal Effects of Motivation and Physical Activity on Depressive Symptoms among College Students.

High prevalence of depression and physical inactivity have been consistently reported among college students, especially in females. Guided by Lubans et al.'s conceptual framework, the primary purpose of this study was to examine the longitudinal relationships of PA motivation with leisure-time PA and depressive symptoms among college students over one academic year. Employing a longitudinal repeated measure design, 1004 college students in China were recruited in this study (28.3% males and 71.7% females; M age = 18.93 ± 0.64 years; 18-22 years old). Participants completed previously validated questionnaires assessing PA motivation (perceived competence beliefs and task values toward PA), leisure-time PA participation, and depressive symptoms in Fall 2016 (Time 1) and Fall 2017 (Time 2). Both male and female college students showed a significant increase of depressive symptoms from freshmen to sophomores (p < 0.05). The regression models indicated that perceived competence beliefs and task values toward PA were significant predictors of depressive symptoms at Time 2 (p < 0.05) after controlling for Time 1 measures in males and females, respectively. Physically active college students consistently demonstrated higher PA motivation, and they displayed fewer depressive symptoms compared to inactive peers over time (p < 0.05). The findings suggest sex-specified motivational intervention strategies and PA promotion programs/opportunities are needed to reduce depression symptoms among college students over time.