Psychotherapy Evaluation and Research Lab at Sheffield (PEARLS)

PEARLS brings together a group of academics, clinicians, research fellows and postgraduate students whose research focuses on the evaluation of routinely delivered psychological interventions.

Taking a pragmatic approach, the Lab’s mission is to better understand and then improve the effects of psychological therapies delivered in routine healthcare settings.

Collectively, our expertise and interests are in the analysis of practice-based datasets and pragmatic trials carried out in clinical settings, to understand how therapy works in routine care, and why clinical outcomes vary across services, therapy models, therapists and patients.

What we do

In order to fulfil our mission to improve routine psychological care through the development of practice-based evidence, we

  • conduct pragmatic trials of psychological therapies in the National Health Service

  • deliver practice-based evidence through analyses of routinely collected data from services

  • adapt existing interventions for maximum effect in routine services

  • generate materials to support psychological therapists in their work (such as therapy manuals and competency measures)

  • undertake selective research consultancy focusing on the analyses of large data sets

  • host research seminars and academic visits from partner Universities and clinical services

  • offer research internships and postdoctoral positions.

Featured articles

Delgadillo, J., Deisenhofer, A.-K., Probst, T., Shimokawa, K., Lambert, M. J., & Kleinstauber, M. (2022). Progress feedback narrows the gap between more and less effective therapists: A therapist effects meta-analysis of clinical trials. Journal of Consulting and Clinical Psychology, 90(7), 559–567. https://doi.org/10.1037/ccp0000747

Power, N., Noble, L. A., Simmonds-Buckley, M., Kellett, S., Stockton, C., Firth, N., and Delgadillo, J. (2022) Associations between treatment adherence-competence-integrity (ACI) and adult psychotherapy outcomes: A systematic review and meta-analysis. Journal of Consulting and Clinical Psychology, 90(5), 427–445.
https://doi.org/10.1037/ccp0000736

Find out more


Featured books

A detailed account of our practice-based research tradition can be found in: Barkham, M., Hardy, G. E., and Mellor-Clark, J. (eds.) (2010). Developing and delivering practice-based evidence: A guide for the psychological therapies. Wiley and Sons.

Bergin and Garfield's handbook of psychotherapy and behavior change (2021) is the pre-eminent research text focusing on psychological therapies. The seventh edition is edited by Michael Barkham (UK), Wolfgang Lutz (Germany) and Louis G Castonguay (US). Wiley and Sons.