Understanding determinants of socioeconomic inequality in mental health in Iran's capital, Tehran: a concentration index decomposition approach

In a cross-sectional observational study, mental health data were taken from an Urban Health Equity Assessment and Response Tool (Urban HEART) survey, conducted on 22 300 Tehran households in 2007 and covering people aged 15 and above. Principal component analysis was used to measure the economic status of households. As a measure of socioeconomic inequality, a concentration index of mental health was applied and decomposed into its determinants.The overall concentration index of mental health in Tehran was -0.0673 (95% CI = -0.070 - -0.057). Decomposition of the concentration index revealed that economic status made the largest contribution (44.7%) to socioeconomic inequality in mental health. Educational status (13.4%), age group (13.1%), district of residence (12.5%) and employment status (6.5%) also proved further important contributors to the inequality.Socioeconomic inequalities exist in mental health status in Iran's capital, Tehran. Since the root of this avoidable inequality is in sectors outside the health system, a holistic mental health policy approach which includes social and economic determinants should be adopted to redress the inequitable distribution of mental health.Mental health is an integral and essential component of health; undeniably, there can be no health without mental health [1,2]. Mental health influences a large range of qualities for individuals and communities, including higher quality of life, better physical health, productivity, social cohesion, and wellbeing [1]. However, mental health is unequally distributed in our societies, meaning that people who live in a socially and economically disadvantaged situation suffer from a disproportionate burden of mental disorders and subsequent adverse consequences [2,3].The etiology of mental disorders is multifactorial; risk is determined by a combination and interaction of biological, psychological, and social determinants [2]. Social determinants have been shown to account for a remarkabl