Abstract

Background
Psychological formulation is a central process in many contemporary evidence-based psychological therapies. Formulation is also considered a core competency of clinical psychology training and practice and is heavily referenced throughout professional standards and guidelines. Despite the significance of formulation in clinical psychology and within wider mental health professions, there is limited evidence to show that formulation benefits the client or improves outcomes in therapy, including the working alliance and measures of distress. Considering the status of psychological formulation, further research is required to examine whether formulation impacts outcomes in therapy.

Aims
The key aims of this study was to investigate whether (1) formulation impacts on working alliance and (2) there is a relationship between formulation, working alliance and psychosocial outcomes. To address these research questions, the study delivered a CBT intervention, incorporating ‘product’ and ‘process’ formulations to adults experiencing low mood.

Method
The study used a repeated single-case A-B, mixed methods design. The design included a non-treatment baseline phase (A), measuring weekly symptoms of low mood and was followed by the intervention phase (B), which consisted of eight weeks of CBT focussing on low mood. The CBT intervention incorporated two ‘product’ formulations (in session 3 and 7) and ‘process’ formulations, which were delivered throughout. Participants and the therapist completed weekly measures at the end of each session, which included measures of working alliance, depression and well-being. Change interviews were also undertaken at the end of therapy to triangulate results. Data analysis mainly included visual analysis, simulation modelling analysis and clinical/reliable change.

Results
Seven participants were recruited, with five participants completing the full eight week CBT intervention. The analysis showed a slight relationship between formulation and working alliance, although evidence was not robust enough to confirm whether formulation directly impacts working alliance. The results showed mixed findings in terms of the relationship between formulation, working alliance and psychosocial outcomes measured. Although over half of participants showed an improvement in depression and two improved in wellbeing, it was not possible to attribute these changes specifically to formulation.

Discussion
This study contributes to a dearth in the literature surrounding the impact of formulation on outcomes in CBT. The findings discussed are mixed and although tentative conclusions can be made that formulation, particularly the product formulation may have contributed to elements of the working alliance, it is not possible to state that formulation directly impacted on the working alliance. The study also highlights the complexity of psychotherapeutic research and the challenges of disentangling processes to draw conclusions on what variables contribute to changes in outcomes. The utility of single-case designs enables researchers to study complex therapeutic processes using a scientific methodology, ultimately bridging the gap between research and clinical practice. This study provides a platform for future research into formulation and should further consider some of the limitations discussed, e.g., does the accuracy of process formulations mediate the working alliance, is it possible to separate the working alliance from the process of formulation.