Integrating group and individual psychotherapy for complex PTSD : A pragmatic case study

Abstract

Introduction

Young’s Schema therapy has shown effectiveness in treating individuals diagnosed with Complex Post-Traumatic Stress Disorder (C-PTSD) (Ubico et al., 2024). Dissociative symptoms are frequently observed in this clinical presentation. However, how do they evolve over the course of treatment ? To address this, we have developed a psychotherapeutic program that integrates group and individual therapy, grounded in Contextual Schema Therapy (Roediger et al., 2018). This program also draws on key principles from psychotraumatology, particularly the theory of structural dissociation of the personality (Van der Hart et al., 2006). While these theoretical frameworks share certain conceptual foundations, they differ in how they understand dissociation and in the therapeutic strategies they propose. Still, given the well-documented influence of therapeutic alliance and group cohesion on treatment outcomes, the common factors model of psychotherapy may offer a valuable, integrative lens. This raises a central question : What mechanisms of change can be observed in an individual with Complex PTSD undergoing a combined group and individual psychotherapy program ?​

Methodology

This study employs a mixed-methods design grounded in Fishman’s (2017) pragmatic case study methodology. Standardized instruments were administered at four time points : pre-treatment (T0), mid-group therapy (T1 ; after 10 sessions), post-group therapy (T2 ; after 20 sessions), and at a three-month follow-up (T3). Variables assessed encompassed complex post-traumatic stress symptoms, psychoform and somatoform dissociative symptoms, quality of life, and the therapeutic alliance. Group cohesion was evaluated at the conclusion of each of the twenty group sessions. The clinician-researcher also conducted monthly assessments utilizing the Dimensions of Therapeutic Movement Instrument (DTMI) for complex trauma. At the conclusion of therapy (T2), an independent clinical psychologist conducted a research interview to explore various dimensions of change. A thematic analysis (Braun & Clarke, 2006) was conducted to identify emerging themes from the interview.

Results. The trajectory of the combined psychotherapy is delineated in detail. By the conclusion of treatment, a substantial reduction in complex post-traumatic symptoms, along with psychoform and somatoform dissociative symptoms, was observed, with these improvements sustained at follow-up. Quality of life also demonstrated notable enhancement. Regarding common therapeutic factors, the therapeutic alliance progressively strengthened throughout the course of treatment. ​In contrast, group cohesion declined sharply at the tenth session but subsequently improved and stabilized following the resolution of a rupture within the group. The research interview highlighted several therapeutic gains, including symptom reduction, the contribution of group therapy, the value of the combined approach, enhanced insight into psychological functioning, improved interpersonal relationships, increased self-confidence, emotional regulation, appropriation of therapeutic tools, and the central importance of the therapeutic relationship.

Discussion. These findings are examined in the context of existing literature on post-traumatic and dissociative symptoms, as well as associated comorbidities. The participant’s integrative process is analyzed through the lens of structural dissociation theory and Liotti’s conceptualization of disorganized attachment in traumatized and dissociative individuals. The study further substantiates the efficacy of schema therapy techniques, including chair work and imagery rescripting. Moreover, the findings align with existing research on common therapeutic factors, highlighting the significance of emotionally salient experiences in facilitating psychological change. This single-case study exemplifies the reciprocal and cyclical interplay between two therapeutic modalities conducive to transformation : individual therapy, which focuses on intrapsychic processes and trauma processing, and group therapy, which centers on interpersonal dynamics.

Limitations and Future Directions. Although the single-case design limits the generalizability of the findings, this study offers promising avenues for future research and clinical innovation.

Key-words : schema therapy ; dissociation ; attachment ; therapeutic alliance ; group cohesion ; change process.