Complex Trauma and Dissociation: The Evolution of Trauma Practice

For over forty years, Kathy Steele has treated patients with severe, chronic trauma and complex dissociation, many of whom had not stabilised in standard treatment settings.

In this Legacy Interview, Kathy Steele reflects on the development of contemporary trauma treatment and considers how decades of work with severe trauma have shaped her clinical thinking, professional judgement and life beyond the consulting room. The conversation also explores how understanding of dissociation has deepened in recent decades, with Kathy helping the field to recognise dissociative processes more clearly and respond to them more responsibly. In conversation with Jane O’Rourke, Kathy was joined by special guests Pat Ogden, Dolores Mosquera and Ana Gomez, whose work brings complementary perspectives on the body, dissociation and developmental trauma with adults and children.

Kathy reflects on how her approach developed in response to clinical situations in which existing models proved insufficient. What was happening in the consulting room that led her to question established approaches? When did she recognise that certain trauma interventions were increasing fragmentation rather than reducing suffering? How did seeing patients become more dissociated, suicidal or fragmented when work moved too quickly shape her judgement about pacing, containment and therapeutic responsibility?

Structural dissociation theory emerged from these clinical pressures. In this interview, Kathy discusses how she and fellow researchers Onno van der Hart and Ellert Nijenhuis came to understand that many trauma patients were organised around distinct survival states rather than a cohesive sense of self, and how that recognition altered formulation and treatment planning. The interview also considers why phase-oriented treatment became necessary in order to reduce iatrogenic harm, and what Kathy observed when therapeutic work moved too quickly.

The conversation also addresses the personal realities of sustaining this work. What does it require to remain clinically present with suicidality, severe dissociation and chronic trauma across decades of practice? How has this level of exposure shaped Kathy’s thinking, her boundaries and her capacity to remain steady? How does a clinician balance the intensity of this field with an ordinary life?

At MINDinMIND, we prepare our Legacy Interviews by examining the conditions in which ideas were formed. We look closely at the patient populations our guests were treating, the services and institutional contexts that shaped their practice, and the clinical impasses that forced them to rethink established approaches. We trace where their thinking changed and why. Drawing on our background in broadcast journalism alongside clinical work, the conversation is structured around these turning points. We ask where an idea first formed, where it faltered, where it had to be revised, and what clinical risk or difficulty drove that revision.

As co-developer of structural dissociation theory, Kathy brought greater precision to understanding how trauma can organise experience into survival-based parts and why stabilisation is central in complex PTSD treatment. Her work has shaped trauma training and service delivery internationally, particularly in how clinicians assess readiness for trauma processing and manage destabilisation risk.

Themes include:

• The clinical realities that led to structural dissociation theory
• Why phase-oriented treatment became a safeguard rather than a preference
• Recognising and preventing destabilisation
• The limits and risks of exposure-based approaches in complex trauma
• Countertransference, endurance and therapist responsibility
• How Kathy’s clinical judgement has evolved across a lifetime of practice

The Panel

Kathy is in conversation with Jane O’Rourke, joined by special guests Pat Ogden, Dolores Mosquera and Ana Gomez.

Pat draws on her longstanding work on how trauma is held and communicated through the body.

Dolores reflects on her work with adults with complex trauma and dissociation, particularly in relation to long-term stabilisation and integration.

Ana addresses how these principles are adapted in work with children and adolescents, where developmental stage and family context alter both pacing and formulation.

This Masterclass focuses on the practical demands of treating complex trauma. The emphasis is on keeping therapy effective without exceeding what a particular patient can tolerate.

Drawing on structural dissociation theory and phase-oriented treatment, Kathy Steele examines the clinical decisions that determine outcome: when to consolidate, when to deepen the work and when to pause.

Complex trauma treatment requires precise attention to how a patient’s internal world is organised, what stabilises it and what risks overwhelming it.

Key questions include:

• How do we adapt intervention to the patient’s internal organisation?
• When is trauma processing clinically appropriate and when is it premature?
• How do we promote integration without increasing fragmentation?
• How do we maintain therapeutic momentum without compromising stability?

The session explores:

• Developing and refining formulation in complex trauma and complex PTSD
• Recognising dissociative processes in routine clinical work
• Working with trauma-related parts to increase cooperation rather than deepen division
• Calibrating pacing within a phased treatment framework
• Identifying early signs of destabilisation and adjusting accordingly