Bidirectional association between sedentary behaviour and depressive symptoms in adolescent girls.

This study examined longitudinal and bidirectional association between sedentary behaviour (SB) and depressive symptoms (DS) in adolescent girls. Participants (n = 253) completed measures of SB and DS at three time points spanning a four-year interval. DS were obtained using the modified Centre for Epidemiological Depression Scale (CES-D). Weekday and weekend SB was assessed using a questionnaire. In the latent growth model, both SB and DS increased and the change in SB was positively associated with change in DS (β = 0.24). Higher levels of SB at baseline were associated with larger increases in DS over time (β = 0.23), and higher baseline levels of DS were associated with smaller increases in SB over time (β = -0.17). These findings suggest persistent longitudinal and bidirectional associations between SB and DS and encourage the design of interventions that limit sedentary time as a possible means of reducing adolescent depression.