The thesis shifts the explanatory framework of depression from the currently predominant clinical model which explains depression as a problem located in the individual, to a social psychological approach which explains depression in terms of its meaning to the individual, as an experience of self, evolved through relationships with others. Theoretically, the thesis draws on Mead's (1934) theory of social hehaviourism, and symbolic interactionism (Blumer 1969). An innovative and interpretative qualitative methodology, "Thematic Analysis", is developed for the analysis of interview accounts acknowledging the perspectives of participants. Analyses are presented as the subjective interpretations of the researcher but accounts are approached as partial representations of real experiences. The methodology of thematic analysis is developed through the research, drawing on grounded theory (Glaser and Strauss, 1967) and discourse analytic techniques (Potter and Wetherell, 1987). The thesis comprises four separate studies to investigate subjective experiences of depression and the meaning of the term "depression", based on in-depth, semi-structured interviews. Study I, an exploratory study with a university population (not necessarily depressed), identifies themes and discourses in accounts of depression. Study II investigates subjective experiences of depression from patients' perspectives, based on accounts of psychiatric out-patients and patients of general practitioners who had been diagnosed as depressed, and identifies the power of the medical discourse in legitimating problems as depression. Study III discusses medical discourses of depression, as used by psychiatrists, general practitioners and clinical psychologists in interview accounts which emphasised the importance of organisational context. Study IV investigates women's experiences of motherhood and depression from participants' perspectives and based on their subjective accounts, and discusses gender identity and the social construction of motherhood as part of their experiences of depression. The analysis indicated that for most respondents depression is both a subjective and a socially constructed experience. The powerful construction of depression as a clinical problem located in the individual may legitimate problematic experiences, hut it is insufficient to explain subjective experiences of depression, which are better understood in terms of the construction of subjectivity through social interaction. The research has implications for more helpful professional and personal approaches to understanding the experience of depression.