Therapist self-disclosure in psychotherapy has traditionally been regarded as something to be avoided. This trend has recently changed: some researchers suggest the efficacy of therapist self-disclosure in therapy. Owing to these results, the focus of the debates has shifted from whether a therapist should self-disclose to the quantitative aspect of self-disclosure in western countries. By contrast, therapist self-disclosure is rarely addressed directly as a research topic in Japan. Therefore, the purpose of the paper was to overview recent research on therapist self-disclosure and to describe the advantages and challenges of therapist self-disclosure in psychotherapy. We begin by reviewing previous research on the definition, type, frequency, purpose, and effects of therapist self-disclosure. We then discuss practical and ethical considerations for the appropriate use of therapist self-disclosure as a therapeutic intervention. The results clarify the trend of therapist self-disclosure during psychotherapy and at the same time identify future issues in therapist self-disclosure.
