This chapter discusses two competing views on depression, one that is biomedical in scope and the other that is grounded in language and social interaction. The discursive-interactional model is contrasted with the more traditional biomedical model of mental illness along three dimensions: diagnosis, cause, and treatment. The chapter begins with an overview of the biomedical model, which takes an intrapersonal, cognitive view of mental illness. Diagnosis of depression is guided by the presence of symptoms taken from a person’s biography or observations of a person’s behavior. The causes of depression are rooted in atypical or maladaptive brain and cognitive functioning. Treatment targets the brain in the form of drug therapy and cognition by means of psychotherapy to restore healthy cognitive performance. Next, the chapter turns to the discursive-interactional model as offering an alternative, interpersonal, and discourse-based perspective on mental illness. In this model, diagnosis is seen as an interactional activity that is accomplished through talk. Causes of depression are connected to social relationships and the social and political structures that may work oppressively. Treatment aligns with a relational perspective by providing empathy and by unpacking client experience to consider alternative perspectives. It aims to place persons’ narrated biographies within their social contexts rather than medicalizing and individualizing problems This chapter concludes by summarizing the importance of examining language and social interaction in real-life situations to further our understanding of how depression talk may be used as evidence to issue diagnosis and how it can inform psychotherapeutic treatment.