Strengths and Limits of Psychodynamic Intervention Rating Scale (PIRS) in Capturing Psychotherapeutic Micro‐Process: A Systematic Review

Background: The Psychodynamic Intervention Rating Scale (PIRS) stands out as one of the most widely utilised coding systems aimed at categorising micro-process from psychotherapeutic dialogue due to its feasibility and adherence to the expressive–supportive continuum. Despite this, no comprehensive analysis of its application in the literature has been published. This systematic review aims to examine the state of the art, strengths, limitations and future perspectives of such a coding tool for verbatim transcripts. Methods: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic search in databases (PsycINFO, Scopus, PubMed and Web of Science) covering publications from the PIRS's first occurrence in the scientific literature in 1992 to 2024 yielded 22 publications eligible for review. Three independent reviewers screened the studies and extracted data regarding PIRS applications and key findings. Results: The studies examined revealed that PIRS can reliably classify interventions across various therapeutic approaches, surpassing its psychodynamic origins. It demonstrated peculiar efficacy in understanding therapeutic alliance mechanisms and patients' responses according to their typical defensive patterns. However, the findings also indicated some limitations concerning the breadth of PIRS categories, which may overlook the essential nuances of micro-processes. Conclusions: While the PIRS has proven its value for understanding clinical micro-process, its categories may be slightly refined. A proposal for a more granular classification of PIRS categories has finally been provided via a literature analysis.