title: Collaboration in the new millennium.
abstract: The presidential addresses of the Society for Psychotherapy Research (SPR) of the past decade convey a consistency of format and themes. They highlight significant weaknesses in some of the basic questions and methodologies of psychotherapy researchers. These include neglect of topics concerning the understanding of change and over-valuation of the randomized clinical trial (RCT). Although valid, the criticisms neglect the strengths of RCTs, which are illustrated by a series of psychotherapy clinical trials conducted by the author's research team, and run the risk of polarizing psychotherapy researchers. The new millennium is an appropriate time to acknowledge how different methodologies complement each other and advance knowledge in ways that could not occur in the absence of others. SPR is an international, multidisciplinary scientific organization that emphasizes inclusiveness. Nevertheless, it, as well as other organizations, can further enhance its contribution to the field by extending its range of collaboration to include underrepresented researchers, disciplines, and research-oriented clinicians.