An Update on the Epidemiology of Major Depressive Disorder Across Cultures

Abstract

Major depressive disorder (MDD) is a recognized and highly prevalent public health issue of worldwide importance. Estimates of prevalence of MDD vary across countries. In general, studies have found a higher prevalence of MDD in high-income countries compared to low- and middle-income countries. There may be methodological issues influencing these estimates, such as differences in symptom expression across cultures, which are modulated by constructs such as gender roles, social expectations, and acceptability of communicating affective states. International epidemiological studies attempting to address methodological challenges and other lines of evidence indicate that there may be substantive factors (differences in genetic vulnerability and environmental risk factors) playing a role on the prevalence estimate variations of MDD. Despite the inherent limitations of this mostly cross-sectional epidemiological data, it confirms MDD is a major public health concern across cultures, indicating associations of MDD with numerous adverse outcomes. Among these outcomes are elevated risks of other psychiatric and medical disorders, in addition to poor functional outcomes in areas such as education, employment status, financial success, teen childbearing, parent functioning, and marital stability. We hope that future epidemiological research will continue to take into account how MDD manifests across different cultures, drawing from work in transcultural psychiatry while designing cross-cultural studies. Investigating the worldwide prevalence of MDD and its associated features may contribute to the proper identification of environmental risk factors for this disorder, which may facilitate the identification of vulnerable individuals, who might benefit from targeted preventative strategies.