Introduction - Depression, through its conceptual and/or etiological frameworks, is a disease that exemplifies the new approaches developed in social epidemiology: biographical epidemiology and contextual epidemiology. The objective of this study is to propose hypotheses for understanding this illness based on the complementarity of these two approaches. Its aim is to investigate an association between potentially traumatic life events in childhood and the onset of depression in adulthood, and to determine whether, after adjusting for individual characteristics associated with depression, differences persist depending on the type of neighborhood of residence. Methods - The SIRS (Health, Inequalities, and Social Disruptions) cohort has been tracking a random sample of 3,000 individuals representative of the French-speaking adult population of Paris and its inner suburbs since 2005. This analysis uses individual data collected in face-to-face interviews at baseline, focusing in particular on participants’ depressive status as assessed using the Mini-Diag, life events, and social conditions during childhood. The socioeconomic type of the IRIS (Clusters for Statistical Information) neighborhood where individuals reside was also taken into account. The analyses employ logistic and multilevel regression models. Results - After adjusting for the subjects’ demographic and socioeconomic characteristics, several biographical events occurring during childhood, as well as certain characteristics of family functioning, appear to be strongly and independently associated with depression on the day of the survey; notably having been a victim of sexual abuse or a witness to interparental violence, but also the fact that parents experienced long periods of unemployment or severe financial difficulties. Furthermore, after adjusting for these individual characteristics, depression remains more prevalent in neighborhoods classified as sensitive urban areas. Conclusion - Several childhood events and living conditions appear to be detrimental to mental health in adulthood, and regional inequalities persist after adjusting for these factors. Such findings reignite the debate on methods for the prevention, information, and screening of depression. (R.A.)