Date of Award


Publication Type

Doctoral Thesis

Degree Name





Antonio Pascual-Leone




Therapist effects, or the differential performance of psychotherapists with respect to client outcome, have long been a noted phenomenon in the psychotherapy literature, but are under-studied (Baldwin & Imel, 2013). Contributors to therapist effects, specifically discrete therapist characteristics such as demographic and personality variables, have been studied for their relation to differential outcomes, but no conclusive associations have emerged (Cooper, 2008). The present dissertation involved the investigation of therapist effects within the context of an outpatient psychotherapy clinic where graduate students in clinical psychology are trained in psychotherapy. In a first study, the clinical outcomes of clients who were treated by therapists who practiced two or more of cognitive behavioural therapy, emotion-focused therapy, brief psychodynamic psychotherapy, and integrative psychotherapy were examined for differential effectiveness of therapists. In a second study, a sample of the same graduate students responded to a questionnaire inquiring about their perspectives on training experiences. Current and former psychotherapy trainees were asked a series of questions about what experiences were helpful, influential, or hindering, among others, to their development. A mixed-methods approach was taken to address these questions. Finally, in a third study, the preceding two investigations were combined to identify relationships between training experiences, as reported by trainees, and psychotherapy performance. Meaningful therapist effects were found regarding both magnitude of change (i.e., raw pre-post symptomatology differences) and efficiency of change (i.e., modeled symptom reduction per therapy session). Multiple structures of themes were identified when therapists reflected on their helpful training experiences, including the importance of feeling supported by supervisors while being encouraged to develop a unique therapist identity, and the perceived value of group and video supervision. Alternately, therapists cited perceived experiences of critical supervisory environments as well as supervisor rigidity as especially hindering. Therapists who had the largest positive associations with client improvement placed high value on didactic training experiences related to doing and being, including engaging in role plays and receiving video supervision. Therapists who were associated with less client improvement compared to their peers placed higher value on didactic experiences that generally provided opportunities for the accumulation of concrete knowledge, including reading about case examples and receiving consultation-based supervision, while placing less emphasis on training experiences that involved ambiguity and nuance. This third study is the first to relate therapist rankings to training experiences and has implications for the optimal training of psychotherapists.