Introduction

Sedentary behaviour is potentially a modifiable risk factor for depression and anxiety disorders, but findings have been inconsistent.

Objectives

To assess associations of sedentary behavior with depression and anxiety symptoms and estimate the impact of replacing daily time spent in sedentary behaviors with sleep, light, or moderate-to-vigorous physical activity, using novel compositional data analysis methods.

Methods

Prospective cohort study in with 60,235 UK Biobank participants (mean age: 56; 56% female). Exposure was baseline daily movement behaviours (accelerometer-assessed sedentary behaviour, physical activity, and self-reported total sleep). Outcomes were depression and anxiety symptoms (Patient Health Questionnaire-9 and Generalised Anxiety Disorders-7) at follow up.

Results

Replacing 60 minutes of sedentary behaviour with light activity, moderate-to-vigorous activity, and sleep was associated with lower depression symptom scores by 1·3% (95%CI, 0·4%-2·1%), 12·5% (95%CI, 11·4%-13·5%), and 7·6% (95%CI, 6·9%-8·4%), and lower odds of depression by 0·95 (95%CI, 0·94-0·96), 0·75 (95%CI, 0·74-0·76), and 0·90 (95%CI, 0·90-0·91) at follow-up.

Replacing 60 minutes of sedentary behaviour with moderate-to-vigorous activity and sleep was associated with lower anxiety symptom scores by 6·6% (95%CI, 5·5%-7·6%) and 4·5% (95%CI, 3·7%-5·2%), and lower odds of meeting the threshold for an anxiety disorder by 0·90 (95%CI, 0·89-0·90) and 0·97 (95%CI, 0·96-0·97) at follow-up. However, replacing 60 minutes of sedentary behaviour with light activity was associated with higher anxiety symptom scores by 4·5% (95%CI, 3·7%-5·3%) and higher odds of an anxiety disorder by 1·07 (95%CI, 1·06-1·08).

Conclusions

Sedentary behaviour is a risk factor for increased depression and anxiety symptoms in adults, but different replacement activities differentially influence mental health.