The theoretical implications of equating the melancholic states of past eras with today's depression are explored. These include the presuppositions of the descriptive psychiatry so influential in twentieth century classification, which attempts to identify and describe mental disorders without reference to underlying causes. It also includes claims made about different forms of masked, and non-Western depression, and the new "drug cartography" assigning psychiatric categories based on psychopharmacological effect. An evaluation of the relative merits of descriptivist and causal ontologies, together with (...) an assessment of the similarities and differences between melancholia and depression, suggest the conclusion that these two conditions are misleadingly equated. (shrink)