Any progress in shaping up an externalist psychiatry, so previous discussion suggested, must begin from questions about the ontology of social causation. So far, research and theory have adhered to a naturalistic approach to the social causes of illness, concentrating mostly on the ‘social determinants of mental health’ (inequality, discrimination, housing insecurity, etc.). The paper starts with an assessment of ‘social determinants’ through the lens of epidemiology and critical psychiatry. It illustrates existing practical and political approaches that fight these constraints and it highlights their therapeutic value. It argues, though, that a focus on social determinants is not sufficient for fully realising externalism because a great portion of sociogenic illness remains causally indeterminate. Alongside political action, externalism requires a social aetiology that is established by virtue of the meaning that it holds for patients, rather than by virtue of its capacity to identify objective social causes of illness. This entails abandoning naturalism about social causation and embracing constructivism. The paper shows that this methodological shift is less contradictory and more effective than it is commonly imagined. Drawing from further anthropological evidence, it concludes that only by lending support to projects that balance a focus on constraints with social construction will psychiatry be truly externalist. At stake is a prospect of effective treatment for sociogenic illness for the countless in struggle
