Some studies in the sociology of stress conceptualize their outcome variables as distress, while others treat the same outcomes as mental disorder. This article focuses on the importance of distinguishing between the two. It argues that there are fundamental differences between distress that arises in non-disordered persons and genuine mental disorder but that studies of stress typically fail to distinguish between these conditions. The article outlines the historical developments that led the field to conflate distress and disorder. Finally, it indicates some advantages for research, treatment and policy that can accrue when distress that is initiated and maintained by social conditions is distinguished from mental disorders that are dysfunctions of internal psychological mechanisms.