Effect of exercise for depression: systematic review and network meta-analysis of randomised controlled trials.

OBJECTIVE: To identify the optimal dose and modality of exercise for treating major depressive disorder, compared with psychotherapy, antidepressants, and control conditions. DESIGN: Systematic review and network meta-analysis. METHODS: Screening, data extraction, coding, and risk of bias assessment were performed independently and in duplicate. Bayesian arm based, multilevel network meta-analyses were performed for the primary analyses. Quality of the evidence for each arm was graded using the confidence in network meta-analysis (CINeMA) online tool. DATA SOURCES: Cochrane Library, Medline, Embase, SPORTDiscus, and PsycINFO databases. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Any randomised trial with exercise arms for participants meeting clinical cut-offs for major depression. RESULTS: 218 unique studies with a total of 495 arms and 14 170 participants were included. Compared with active controls (eg, usual care, placebo tablet), moderate reductions in depression were found for walking or jogging (n=1210, κ=51, Hedges' g -0.62, 95% credible interval -0.80 to -0.45), yoga (n=1047, κ=33, g -0.55, -0.73 to -0.36), strength training (n=643, κ=22, g -0.49, -0.69 to -0.29), mixed aerobic exercises (n=1286, κ=51, g -0.43, -0.61 to -0.24), and tai chi or qigong (n=343, κ=12, g -0.42, -0.65 to -0.21). The effects of exercise were proportional to the intensity prescribed. Strength training and yoga appeared to be the most acceptable modalities. Results appeared robust to publication bias, but only one study met the Cochrane criteria for low risk of bias. As a result, confidence in accordance with CINeMA was low for walking or jogging and very low for other treatments. CONCLUSIONS: Exercise is an effective treatment for depression, with walking or jogging, yoga, and strength training more effective than other exercises, particularly when intense. Yoga and strength training were well tolerated compared with other treatments. Exercise appeared equally effective for people with and without comorbidities and with different baseline levels of depression. To mitigate expectancy effects, future studies could aim to blind participants and staff. These forms of exercise could be considered alongside psychotherapy and antidepressants as core treatments for depression. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42018118040.

An umbrella review of the benefits and risks associated with youths' interactions with electronic screens.

The influence of electronic screens on the health of children and adolescents and their education is not well understood. In this prospectively registered umbrella review (PROSPERO identifier CRD42017076051 ), we harmonized effects from 102 meta-analyses (2,451 primary studies; 1,937,501 participants) of screen time and outcomes. In total, 43 effects from 32 meta-analyses met our criteria for statistical certainty. Meta-analyses of associations between screen use and outcomes showed small-to-moderate effects (range: r = -0.14 to 0.33). In education, results were mixed; for example, screen use was negatively associated with literacy (r = -0.14, 95% confidence interval (CI) = -0.20 to -0.09, P ≤ 0.001, k = 38, N = 18,318), but this effect was positive when parents watched with their children (r = 0.15, 95% CI = 0.02 to 0.28, P = 0.028, k = 12, N = 6,083). In health, we found evidence for several small negative associations; for example, social media was associated with depression (r = 0.12, 95% CI = 0.05 to 0.19, P ≤ 0.001, k = 12, N = 93,740). Limitations of our review include the limited number of studies for each outcome, medium-to-high risk of bias in 95 out of 102 included meta-analyses and high heterogeneity (17 out of 22 in education and 20 out of 21 in health with I2 > 50%). We recommend that caregivers and policymakers carefully weigh the evidence for potential harms and benefits of specific types of screen use.

Lifestyle behaviors predict adolescents bullying victimization in low and middle-income countries.

BACKGROUND: In this study we aimed to provide a global perspective of the association between different lifestyle behaviors and bullying in school adolescents and to ascertain whether or not the Human Development Index moderated those associations. METHODS: Data from the Global school-based Student Health Survey were analyzed in 273 121 from 82 countries. Logistic regression was applied to determine country-specific bullying victimization probability from meeting the recommended guidelines for physical activity, excessive sitting time, physical education attendance and active transport. Meta-analysis was then undertaken to ascertain pooled global effect estimates of the relationship between these behaviors and bullying victimization. Linear regression was used to study the relationship between odds of bullying from meeting the lifestyle guidelines and the Human Development Index. RESULTS: Our estimates indicate that excessive sitting time [1.38 (1.34,1.41)], attendance to physical education [0.87 (0.85,0.89)], and active transport [0.94 (0.91,0.97)] but not overall physical activity [1.01 (0.99,1.04)] were associated with bullying in the study sample. LIMITATIONS: The present study is limited by its cross-sectional nature. Also, only two countries were surveyed from the European region CONCLUSIONS: Active commuting and attendance to physical education play a protective role for bullying, while physical activity does not.