Therapeutic discourse is the talk in interaction between clinician and client that aims to improve the mental health of a client. Therapeutic discourse can be conducted in a wide range of institutional settings, varying from primary-care medicine, to rehabilitation and social work. In psychotherapy, therapeutic discourse is the key activity, as the sole business of the psychotherapeutic encounter is to talk and interact in ways that improve the client's mental health. Early studies of therapeutic discourse Therapeutic discourse has been an interest of social scientific and linguistic research from as early as the 1950s. Qualitative interaction analysis of audio-or video-recorded psychotherapy sessions was started by Pittenger, Hockett, and Danehy (1961), who described in detail an audio recording of the first five minutes of an initial psychiatric interview. They paid particular attention to the implicit meanings conveyed by the lexical and prosodic choices of the participants. The major milestone was Labov and Fanshel's book Therapeutic Discourse (1977) in which they analyze a single, 15-minute long segment of psychotherapy interaction using speech act theory. In their analysis, Labov and Fanshel single out four basic types of actions: metalinguistic action (initiating, continuing, or ending an action), representation, request, and challenge. Through the examination of these actions, the authors address themes that are pertinent also in the clinical understanding of psychotherapy, such as emotion and repression. The early studies employed a major part of the concepts and tools of linguistic and social scientific interaction research. Therapeutic discourse has, however, also been studied in other disciplines. Psychotherapy process research is perhaps the most comprehensive research field for understanding therapeutic discourse. Psychotherapy process research Due to the centrality of language and interaction in psychotherapy, themes pertaining to therapeutic discourse are addressed not only in linguistic and social scientific research, but also in clinical and psychological research on psychotherapy. There is a rich research tradition on processes through which psychological change in the client occurs during