American Journal of Epidemiology © The Author(s) 2021.Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com. Vol. 190, No. 7 https://doi.org/10.1093/aje/kwab002 Advance Access publication: January 11, 2021 Systematic Review and Meta- and Pooled Analysis Is the US Gender Gap in Depression Changing Over Time? A Meta-Regression Jonathan M. Platt ∗ , Lisa Bates, Justin Jager, Katie A. McLaughlin, and Katherine M. Keyes ∗ Correspondence to Dr.Jonathan M.Platt, Department of Epidemiology, Mailman School of Public Health, Columbia University, 722 W.168th Street, New York, NY 10032 (e-mail: jmp2198@cumc.columbia.edu). Initially submitted February 26, 2020; accepted for publication October 6, 2020. The depression gap refers to higher rates of depression among women than men. Change in the depression gap over time might elucidate social causes of this disparity—such as unequal college attendance or employment status. We conducted a meta-regression analysis to estimate variation in the depression gap over time by age, accounting for potential sources of variation between studies. Electronic databases and bibliographies were searched for English-language studies from January 1980 through October 2019; 144 independent estimates from US-representative samples met selection criteria (n = 813,189). The depression gap was summarized as prevalence ratios among studies using diagnostic instruments and as standardized mean differences among symptom-based studies. Primary study measures were baseline study year (range, 1982–2017) and age (age groups ranging, in years, from 10–59 and 60 or older). Compared with respondents aged ≥60 years, depression prevalence was greater among respondents aged 10–19 (prevalence ratio = 1.26, 95% confidence interval: 1.02, 1.56).Over time, the depression gap did not change among adults, but it increased among adolescents (age-by- time interaction prevalence ratio = 1.05, 95% confidence interval: 1.01, 1.08). Results were similar for symptom- based studies. The present study finds no evidence of a change in the depression gender gap for US adults; however, the gap increased among adolescents. Greater attention to factors driving this widening disparity in adolescent depression is needed. depression; depressive symptoms; gender; health disparities; time trends; United States Abbreviations: CI, confidence interval; PR, prevalence ratio. Editor’s note: An invited commentary on this article appears on page 1207. Major depressive disorder is the leading cause of disabil- ity among Americans ages 15–44 years (1) and is more likely to affect women than men (2). This pattern, here- after referred to as the depression gap, reflects meaningful differences in depression and is not solely an artifact of gender differences in reporting mental health symptoms or seeking treatment (3, 4). Also, even though the quantitative surveys providing evidence regarding the depression gap typically rely on binary categories that do not differentiate between sex assigned at birth and gender expression, the gap is typically described using the term gender. Given that caveat, we use gender throughout the present study. The depression gap emerges in early adolescence, remains relatively stable throughout adulthood, and then decreases at later ages (5). Biological (6) and social stress (7) mech- anisms have been explored to explain the gap, with the most robust evidence to date supporting social stress. As applied to gender, social stress theory suggests that gender might influence stress exposure and responses (8). In par- ticular, women traditionally have had fewer opportunities in attaining higher education and full-time employment, which might act as social stressors (9). From an early age, women are typically socialized, through gender norms, to respond to stressors in depressogenic ways (10, 11). These factors might increase women’s depression risk, and explain gender differences in depression (9). If so, changes in women’s social positions, and therefore changes in these factors, should change the depression gap in turn. Since the mid-20th century, education (12) and employ- ment (13, 14) opportunities have become increasingly avail- able to women. These changes in gendered social positions 1190 Am J Epidemiol. 2021;190(7):1190–1206 Downloaded from https://academic.oup.com/aje/article/190/7/1190/6071898 by guest on 07 April 2023