ORIGINAL PAPER Opening Up: Therapist Self-Disclosure in Theory, Research, and Practice Margaret F. Gibson Published online: 11 April 2012 Ó Springer Science+Business Media, LLC 2012 Abstract While most therapists report that they do dis- close some information about themselves to their clients, therapist self-disclosure continues to be both controversial and nebulous in clinical theory, research, and practice. This article considers what makes therapist self-disclosure so challenging to define and study and provides an overview of the empirical and theoretical literature. It then concludes with a consideration of therapist self-disclosure in con- temporary legal, ethical, and technological contexts of clinical work. Keywords Self-disclosure Á Theory Á Practice research Á Feminist practice Á Psychodynamic theories Á Humanistic theories Á Sexuality Á Illness Á Disability Á Best practices Á Ethics Á Common factors Á Reflexive practice Introduction Therapist self-disclosure is extremely common, with over 90 % of practitioners reporting that they disclose infor- mation about themselves to their clients at least occasion- ally (Henretty and Levitt 2010). Every major practice tradition has written about what constitutes ‘‘appropriate’’ and ‘‘inappropriate’’ uses of therapist self-disclosure (TSD), sometimes at length (Farber 2006; Weiner 1983; Zur 2007). However, despite its near-universal application and the considerable volume of writing addressing it, TSD continues to be controversial in the practice literature. In this paper, I examine some of the ways in which the concept may be defined and the theoretical underpinnings of these definitions. I go on to discuss the existing research into the uses and effects of TSD, looking first at the chal- lenges of conducting this research, then summarizing some findings on who is using TSD, when, with whom, and with what effects. This exploration considers the impact of diverse social locations of therapists and clients. I then examine how TSD is addressed in different practice theo- ries, and how it connects to other ‘‘common factors’’ of therapy and pan-theoretical ethical and legal responsibili- ties. Finally, I consider the impact of the Internet on TSD in the 21st century. Research Practice and Self-Disclosure How do we write or think about self-disclosure without self-disclosing? Different research epistemologies have varying assumptions about the self of the writer/researcher in social work knowledge. Broadly speaking, the more post-positivist or positivist research traditions posit that the researcher’s beliefs should be transformed into clear, a priori hypotheses, but that the research design should then minimize the impact of the particular researcher with an ideal of ‘‘replicability’’ (i.e. any other researcher would get the same or similar findings with the same hypotheses and design) (e.g. Singleton and Straits 2010). Then, when the research is presented or published, post-/positivist researchers seldom explicitly discuss the researcher’s experience and location, beyond general statements about the limitations of the sample or the terminological defini- tions selected. In contrast, qualitative and interpretivist tra- ditions of social work research usually assume that the researcher is inextricably implicated throughout the research M. F. Gibson (&) Factor-Inwentash Faculty of Social Work, University of Toronto, 246 Bloor Street West, Toronto, ON M5S 1V4, Canada e-mail: margaret.gibson@utoronto.ca 123 Clin Soc Work J (2012) 40:287–296 DOI 10.1007/s10615-012-0391-4