Self- and other-diagnosis in user-led mental health online communities.

This article consists of a qualitative analysis of discussion forums in online mental health communities whose members routinely write about diagnosis. The analysis concerns the function of diagnosis from the perspective of personal identity, with particular focus on the status of official diagnosis, as well as community members' discussions of symptoms and psychiatric syndromes that amount to informal diagnosis or consultation. Self-diagnosis sometimes takes the form of recommended "quizzes" and other online quasi-diagnostic tools. Other-diagnosis, in which a third party is discussed by community members, is also considered. We discuss the implications of such online discourse for Internet users themselves as well the challenges for the health and medical professions.