Is the US Gender Gap in Depression Changing Over Time?

A Meta-Regression

Jonathan M. Platt; Lisa Bates; Justin Jager; Katie A. McLaughlin; Katherine M. Keyes

Disclosures

Am J Epidemiol. 2021;190(7):1190-1206. 

In This Article

Abstract and Introduction

Abstract

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.

Introduction

Major depressive disorder is the leading cause of disability among Americans ages 15–44 years[1] and is more likely to affect women than men.[2] This pattern, hereafter 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] mechanisms 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 particular, 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 employment[13,14] opportunities have become increasingly available to women. These changes in gendered social positions likely reflect broader changes in norms and the process of gender socialization, which might influence both exposure and response to stressors, and might decrease the depression gap in adults in turn. Among adolescents, depressive symptoms have been increasing since 2012, to a greater extent among girls compared with boys.[15] While the underlying factors contributing to the increase remain only speculative, the increase among young women might, unlike among adults, suggest an increasing gender gap.

Available evidence suggests that the depression gap might be changing[16,17] but is inconclusive, in part due to 3 limitations. First, follow-up periods in single longitudinal studies are often too short to identify temporal trends in depression. Second, while existing studies suggest that the depression gap might vary over time, there could also be variation by age across time. Examining variation by both age and time is necessary to identify any temporal variation due to social change. Among reviews that have directly accounted for age in assessing temporal variation in the depression gap, most have focused on a single age group or developmental period.[18,19] A wide time span with age groups across the life course is necessary in order to fully characterize variation in the depression gap by both age and time. Third, less attention has been paid to gender differences in levels of depressive symptoms, which might be distinct from diagnostic depression categories.[20]

We conducted a systematic review, meta-analysis, and meta-regression to characterize changes in the depression gap over time and across the life course. First, studies of gender differences in depression in recent decades were identified and summarized. Second, data from the systematic review were extracted to form the analytical sample of the meta-regression, which estimated the variation in the gap over time by age and accounted for other potential sources of variation between studies. Trends in the depression gap were considered separately based on diagnostic versus symptom-based depression tools, to explore whether variation has been different at a diagnostic threshold versus total depression symptoms.

Comments

3090D553-9492-4563-8681-AD288FA52ACE

processing....