The increasing importance of symbolic and emotional forms of labor in capitalism and the democratic profusion of mood disorders such as depression are major dynamics of the social life of late modernity in the US. These elements of human life are treated as separate in our received, cultural categories, but experientially they seem to converge. Using methods of Foucauldian genealogy and critical theory, I excavate the history of this relationship and theorize its contemporary dynamics. The genealogy starts with medieval acedia, a condition in which inability to work and depressed affects appear as a single problem. Acedia is a partial predecessor of modern conditions such as sloth, ennui, and melancholia, the divisions of which trace affective and social divisions emerging over the course of industrial, capitalist modernity. Late modern capitalism generates types of work and work processes which I characterize as subjective labor, forms of work which require symbolic and affective aspects of workers' subjectivities and intersubjective relationships. Management of workers' moods and initiative becomes central to late capitalism. Late modernity articulates mental normalcy as a positive optimization of mood rather than eradicating abnormalities and a range of techniques of self care emerge, including anti-depressants, short-term psychotherapy, and alternative techniques such as meditation, mindfulness, and stress reduction. Both on the job and in "private" life, mood appears as a problem to be managed. Public discourses of depression are anachronistic at best if they treat work as a secondary question. At a philosophical level, this genealogy implies a need to historicize the concept of alienation. Marxian alienation is premised on the production of physical goods in an industrial labor process. Industrial production and managerial techniques are still central to capitalism as a whole, but in advanced capitalist countries, subjective labor becomes politically and arguably economically much more central. Alienation in an economy dominated by subjective labor can be less about a separation between the worker and the product and activity of labor and more about dissociation within the worker's subjectivity. This renders late modern alienation as a problem which is irreducibly psychological and tied up with other dimensions of affective life.