Social context and depression after a disaster: the role of income inequality

STUDY OBJECTIVE: To examine the association between neighbourhood income inequality and depression, both overall and among those with different levels of income, in the post-disaster context. DESIGN: A representative cross sectional random digit dial telephone survey was conducted. SETTING: New York City (NYC) six months after September 11, 2001. PARTICIPANTS: 1570 respondents were interviewed, of whom 1355 provided residence information permitting their inclusion in this analysis. Past six month depression was assessed using a lay administered instrument consistent with DSM-IV criteria. Income inequality was measured with the Gini coefficient. MAIN RESULTS: The sample was demographically representative of NYC (56.2% female, 35.7% white, 6.3% Asian 24.2% African American, 29.7% Hispanic, and 4.2% other race or ethnicity) and the prevalence of past six month depression was 12.4%. In a final adjusted model, neighbourhood level income inequality was positively associated with depression but this association was not significant (beta = 7.58, p = 0.1). However, among those with low individual income (< 20,000 US dollars) there was a strong significant association between income inequality and depression (beta = 35.02, p<0.01), while there was no association among those with higher income. CONCLUSIONS: In the post-disaster context, neighbourhood level income inequality was associated with depression among persons with lower income; this group may be more socially or economically marginalized and dependent on local resources. Future research should examine potential mechanisms through which income inequality and other features of the social context may affect mental health in the post-disaster context.