A Multidimensional Assessment of Therapeutic Outcomes: Toward a Psychodynamic Diagnostic Manual (PDM-2)-Oriented Approach to Psychotherapy Research

The Psychodynamic Diagnostic Manual-2nd edition (PDM-2) stresses the importance of putting the complex person back at the center of the diagnostic, therapeutic, and research process, fostering the integration between categorical and dimensional classifications, and emphasizing both individual variations and commonalities. Accordingly, the manual aims to promote a new impetus in the psychotherapy research field, trying to bridge the gap between empirical and clinical perspectives. In the present study, a sample of 12 patients diagnosed with borderline personality disorder (BPD), who underwent 1 year of transference-focused psychotherapy, was interviewed using the Adult Attachment Interview (AAI) at baseline and after treatment. The Psychodiagnostic Chart-2 (PDC-2) of the PDM-2 was applied to AAIs, specifically focusing on the level of personality organization and mental functioning capacities (M-Axis). The Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders (DSM-5) Axis II Personality Disorders was also used to provide a categorical measure of therapeutic outcomes. As expected, a significant reduction in the DSM BPD criteria number was observed after treatment. More importantly, there were improvements in terms of overall level of personality severity in almost all PDC-2 M-Axis domains. To the best of our knowledge, this is the first study to show psychodynamic therapeutic outcomes using the PDM-2 framework. Findings underline the importance of promoting a multidimensional approach that integrates descriptive and functional understandings of treatment outcomes, highlighting the relevant contribution of the clinically sensitive and diagnostically accurate PDM-2 approach.