Table 6.

Findings From the Updated Search

Review	Study aim	Included primary studies and study overlap	Study findings	Data extraction and AMSTAR scores
Zimmermann et al.37	To identify studies that examined the modifiable risk and protective factors for anxiety disorders among adults in the general population.	A total of 19 primary studies included in their review. Of these, 2 prospective studies were for the outcome: incident anxiety. These 2 primary studies were included in previous reviews from our initial search.	Authors conducted a qualitative synthesis. One primary study found that when compared with no exercise, regular exercise was found to be a protective factor for agoraphobia and specific phobia. Nonregular physical activity was a protective factor only for agoraphobia. The second primary study found that general physical activity did not predict the onset of any anxiety disorder, but sports participation appeared to be a protective factor in the onset of any anxiety disorder.	We extracted data for the 2 primary studies as reported in the Zimmermann et. al. review. This is reported in Appendix Table 8 (available online) where we give a summary of the characteristics of included reviews from the updated search. Low-quality review.
Brady et al.38	To systematically review the literature on accelerometer-measured physical activity and health outcomes in adults.	Of 52 primary studies included in their review, only 1 was related to our review outcome (incident depression), a new primary cohort study published in 2020.	From the one primary study included for the outcome, depression, women in the lowest tertile of light physical activity (68.1 min/day) had a statistically significant increased risk of developing depressive symptoms, compared with those in the highest tertile (130.0 min/day) (HR=1.98, 95% CI=1.19, 3.29) but not in men (p-interaction<0.01). (light physical activity tertiles, mean [SD]: lowest: 68.1 [11.3] min/day, middle 95.3 [6.5] min/day, highest 130.0 [20.9] min/day)	Because only 1 primary study in their review reported on our study outcome, we did not extract data for this review or assess for review quality.
Dishman et al.39	They quantified the cumulative association of customary physical activity with incident depression and with an increase in subclinical depressive symptoms over time as reported from prospective observational studies They define incident depression by clinical diagnosis or cut points on depression screening tests.	A total of 111 reports included in their review. From their report, we could not distinguish between primary studies reporting incident depression and those reporting subclinical depressive symptoms over time. We did not carry out an analysis of the included primary studies.	Authors defined incident depression by clinical diagnosis or cut points on depression screening tests. The authors found that both odds of incident cases of depression or an increase in subclinical depressive symptoms were reduced after exposure to physical activity. They report that results were materially the same for incident depression and subclinical symptoms (OR=0.69, 95% CI=0.63, 0.75, I2=93.7, and adjusted OR=0.79, 95% CI=0.75, 0.82, I2=87.6).	We did not carry out data extraction for our selected data items or assess review for quality. This was because we could not distinguish between primary studies reporting incident depression and those reporting subclinical depressive symptoms over time. From additional information in their supplementary file, our inclusion criterion for population was not fully met for some of the primary studies.
Guo et al.40	To quantify the relationship between different physical exercise doses and the risk of depression	A total of 12 primary studies all reporting on incident depression. Of these, 8 prospective studies are included in previous reviews from our initial search.	Authors found a nonlinear relationship between leisure time physical activity and the risk of incident depression. The categorical dose–response association: Compared with the lowest LTPA category, the risk of incident depression was 23% lower for all LTPA categories (RR=0.77, 95% CI=0.68, 0.86, I2=69%) and 27%, 17%, and 8% lower for light, moderate, and highest-dose LTPA participants (RR=0.73, 95% CI=0.64, 0.82, I2=43%; RR=0.83, 95% CI=0.78, 0.87, I2=46%; RR=0.93, 95% CI=0.86, 0.99, I2=79%, respectively). Continuous dose–response association: When physical activity was <25 MET-h/week, they found that the RR of depression risk was reduced by 3% for every 5 MET-h/week increase (RR=0.97, 95% CI=0.95, 0.98). When physical activity was >25 MET-h/week, the increased physical activity did not further reduce the risk of depression, that is, the risk of depression increased by 4% for every 5 MET-h/week increase (RR=1.04, 95% CI=1.02, 1.05).	We extracted data and give a summary of the characteristics of study in Appendix Table 8 (available online) Low-quality review
Pearce et al.41	To systematically review and meta-analyze the dose–response association between physical activity and incident depression from published prospective studies of adults.	A total of 15 primary studies all reporting on incident depression. Ten of these primary studies are included in previous reviews from our initial search.	The authors found an inverse curvilinear dose–response association between physical activity and incident depression, with steeper association gradients at lower activity volumes. (those accumulating half the recommended volume of physical activity by 18% [95% CI=13%, 23%] lower risk of depression. Those accumulating the recommended volume had 25% [95% CI=18%, 32%] lower risk, diminishing additional potential benefits and greater uncertainty at higher volumes of physical activity.)	We extracted data and give a summary of the characteristics of study in Appendix Table 8 (available online) Low-quality review.

For the updated search conducted on October 15, 2022, data extraction and assessment of the methodologic quality of the included systematic reviews were done by MNW. This was checked and discussed with JLV.

AMSTAR, Assessment of Multiple Systematic Reviews; HR, hazard ratio; I², I-squared statistic; LTPA, leisure-time physical activity; MET-h/week, MET hours per week, min, minute.