In the 2000s, several psychiatrists cited the lack of relational disorders in the DSM-IV as one of the two most glaring gaps in psychiatric nosology, and campaigned for their inclusion in the DSM-5. This campaign failed, however, presumably in part due to serious “ontological concerns” haunting such disorders. Here, I offer a path to quell such ontological concerns, adding to previous conceptual work by Jerome Wakefield and Christian Perring. Specifically, I adduce reasons to think that collective disorders are compatible with (...) key metaphysical commitments of contemporary scientific psychiatry, and argue that if one accepts the existence of mental disorders in individuals as medical, then one has good reasons to accept the existence of collective disorders as medical. First, I outline how collective disorders are reconcilable with both the harmful dysfunction model of disorder and a denial of mind-body dualism. I then identify some potential weaknesses in the main pre-existing example of a collective disorder, offering my own examples as supplements. These examples’ medical plausibility is bolstered by: work in philosophy of biology on the generalized selected effects theory of function, and work in analytic philosophy of mind on collective mentality. Finally, after offering preliminary responses to the objection that the recognition of collective disorders may lead to an overpathologization of everyday life, I spell out ways in which this recognition may have empowering effects for some would-be patients; for example, by providing substance to the notion of a “sane response to an insane world.”. (shrink)