Opioid abuse is an increasingly global phenomenon. Rather than assuming it to be a uniformly global or neoliberal pathology, how might we better understand comparative and locally specific dimensions of opioid addiction? Working with neighborhoods as a unit of analysis, this article analyzes the striking differences between patterns of addiction and violence in two proximate and seemingly similar urban poor neighborhoods in Delhi, India. Rather than global or national etiologies, I suggest that an attention to sharp ecological variation within epidemics challenges social scientists to offer more fine‐grained diagnostics. Using a combination of quantitative and ethnographic methods, I show how heroin addiction and collective violence might be understood as expressions of what Durkheim called “suicido–genetic currents.” I suggest the idea of varying currents as an alternative to the sociology of neighborhood “effects” in understanding significant differences in patterns of self‐harm and injury across demographically similar localities.