Developing of potential benchmarking tools that enable trainee-therapists, supervisors and educational institutions to quickly assess therapeutic performance can become part of a holistic assessment of a trainee-therapist's clinical development. Despite an inherent optimistic belief that therapists do not cause harm, there appears to be a small and significant proportion of trainee-therapists who consistently evidence little therapeutic change. Considerable variability in trainee-therapists' therapeutic efficiency and effectiveness can exist in the one training programme. Early client dropout may not be associated with therapists' therapeutic effectiveness and efficiency.

Reflexive therapeutic conversations characterized by a greater use of observational language were associated with positive therapeutic outcomes. Therapeutic conversations characterized by a high proportion of questioning language were associated with poorer therapeutic outcomes. Supervisors of trainee-therapists have a key role in coaching supervisees to use language that contributes to client treatment outcomes.

BackgroundContemporary psychotherapy research demonstrates that whilst most clients respond positively to psychological interventions, a small but significant proportion of clients fail to experience the expected benefits of therapy. Although methodologies exist that enable the identification of successful and unsuccessful therapy, we have a limited understanding of the processes associated with these outcomes.AimThis study sought to examine the relationship between therapeutic outcome and therapeutic language.MethodologyTherapeutic outcomes of 42 trainee–therapists who provided psychotherapy to 173 clients were tracked with the OQ‐45.2 over a five‐year period with the view of identifying the client/trainee–therapist dyads with the best and poorest outcomes. The six best outcome and six poorest outcome client/trainee–therapist dyads were identified to examine characteristics of therapeutic conversations associated with better and poorer therapy outcomes. Therapeutic conversations were analysed with the Narrative Process Coding System.FindingsBest outcome client/trainee–therapist dyads demonstrated significant increases in reflexive conversation over the course of psychotherapy. Implications: Examining the practices of best and poorest outcome client/trainee–therapist dyads with objective measures of therapy outcome provides an important first step in understanding how therapeutic language may contribute to the greatest therapeutic improvement or deterioration.