Psychotherapists' self-reports of their interpersonal functioning and difficulties in practice as predictors of patient outcome.

The need for psychotherapy research to understand the therapist effect has been emphasized in several studies. In a large naturalistic study (255 patients, 70 therapists), this topic was addressed using therapists' self-assessed difficulties in practice and interpersonal functioning in therapeutic work as predictors of patient outcome in three conventional outcome measures. Three-level growth curve analyses were employed to assess whether the therapist characteristics, measured by the Development of Psychotherapists Common Core Questionnaire (Orlinsky & Rønnestad, 2005), predicted the level of and change in patient symptom distress (SCL-90R), interpersonal problems (IIP-64), and observer-rated global functioning (GAF). Preliminary estimates of therapist effects in patient change indicated that 4% of change in general symptom distress (GSI), almost 21% of change in IIP global scores, and 28% of growth in GAF could be attributed to therapist differences. The results also demonstrated that certain therapist self-perceptions were clearly related to patient outcome. For example, therapists' scores on a type of difficulty in practice called "Professional self-doubt" (PSD) (denoting doubt about one's professional efficacy) were positively associated with change in IIP global scores. It is suggested that therapists' self-reported functioning can be of value in understanding how individual therapists contribute to therapeutic change although their influence is not necessarily exerted in expected directions.