When working with PTSD, a formulation helps therapists and clients understand why symptoms persist long after a traumatic event has ended.

Rather than focusing only on diagnostic criteria, a cognitive behavioral formulation identifies the psychological processes that maintain a client’s sense of current threat. A PTSD formulation provides a framework for linking intrusive memories, appraisals, triggers, emotional responses, and coping strategies into a coherent understanding of the client’s difficulties.

Post-traumatic stress disorder (PTSD) is a common reaction to traumatic experiences involving actual or threatened death, serious injury, or sexual violence. Symptoms can include intrusive memories, nightmares, flashbacks, avoidance, hypervigilance, shame, guilt, emotional numbing, and heightened physiological arousal. Lifetime prevalence estimates suggest PTSD affects approximately 8.3% of people (Kilpatrick et al., 2013).

One of the most influential cognitive behavioral accounts of PTSD was proposed by Anke Ehlers and David Clark (2000). Their model addresses an important clinical question: if the trauma is over, why does the person continue to experience intense fear and danger in the present?

According to the model, PTSD persists because trauma memories, appraisals, and coping strategies combine to create an ongoing sense of serious current threat.

In this article, we’ll explore how to formulate PTSD using Ehlers and Clark’s cognitive model. Clinicians will learn about the key components of a PTSD CBT formulation, including trauma memories, appraisals, triggers, re-experiencing symptoms, and coping strategies, as well as practical tips for developing collaborative formulations that guide effective treatment.

Understanding the Ehlers and Clark Cognitive Model of PTSD

Ehlers and Clark (2000) proposed that trauma memories in PTSD have distinctive qualities that make them feel current rather than historical.

These memories are often experienced involuntarily and may be fragmented, vivid, emotionally intense, and highly sensory in nature. Clients frequently report ‘nowness’ during flashbacks, describing the experience as though the trauma is happening again in the present moment.

The model also emphasizes the importance of appraisals. Clients may develop negative meanings about the trauma, themselves, other people, or the world. These appraisals can concern the trauma itself (“I’m going to die”), its consequences (“I’m going mad”), externally directed beliefs (“The world is unsafe”), or internally directed beliefs (“I am to blame,” “I’m broken”).

Coping responses are equally important within the formulation. Strategies such as avoidance, thought suppression, rumination, distraction, substance use, or emotional withdrawal are often understandable attempts to reduce distress. However, Ehlers and Clark (2000) proposed that these strategies unintentionally maintain PTSD because they prevent trauma memories and appraisals from being updated.

Key Elements of a PTSD CBT Formulation

The traumatic event

Early formulation work should establish a concise understanding of what happened without encouraging prolonged exposure to traumatic details.

When formulating with clients, therapists are encouraged to help clients briefly describe the traumatic event in their own words. At this stage, it is often clinically useful to explore how the client’s body and mind responded during the trauma, including involuntary reactions such as freezing, dissociation, or emotional shutdown.

Overly detailed trauma exploration early in treatment may increase distress, dissociation, or derail collaborative formulation work.

Trauma memories

Trauma memories in PTSD differ from ordinary autobiographical memories.

They are often involuntary, emotionally intense, and sensory in quality. Clients may re-experience sounds, smells, tastes, bodily sensations, or visual images linked to the trauma.

Research and clinical observation suggest that intrusive memories and flashbacks frequently center around a limited number of highly distressing moments within the trauma memory. These moments are sometimes referred to as “hotspots.”

Identifying these hotspots can help therapists understand which aspects of the trauma continue to drive re-experiencing symptoms.

Appraisals during and after trauma

Distinguishing between appraisals made during the trauma and beliefs that developed afterwards can add important clinical depth to a formulation.

Peri-traumatic appraisals may include thoughts such as “I’m going to die,” “I can’t escape,” or “they’re going to hurt me.”

Post-traumatic appraisals often involve broader conclusions about the self, other people, or the future, including beliefs such as “I’m weak,” “I can’t trust anyone,” or “I’ll never recover.”

According to Ehlers and Clark (2000), these appraisals contribute directly to the client’s ongoing sense of current threat.

PTSD triggers and re-experiencing

People with PTSD are often highly sensitive to environmental reminders associated with their trauma. Triggers can include sights, sounds, smells, places, people, conversations, bodily sensations, or situations that resemble aspects of the traumatic experience.

Careful identification of triggers is clinically important because triggers often explain why symptoms appear suddenly or, seemingly, unpredictably. For example, a smell, facial expression, or physical sensation may activate trauma memories outside conscious awareness, leading to flashbacks, panic, shame, or dissociation.

Understanding current threat in PTSD

A central feature of PTSD is the experience of ongoing threat in the present.

When clients experience intrusive memories, they may experience intense emotions, physiological arousal, hypervigilance, shame, guilt, anger, or helplessness. Memories and other triggers can activate here-and-now appraisals linked to current threat.

A PTSD CBT formulation connects these elements, and can help clients to trace the sequence

Formulation helps connect these present-day reactions to trauma memories and appraisals, allowing symptoms to become understandable rather than frightening or confusing.

PTSD CBT Formulation Resources for Therapists

Developing a PTSD formulation can be challenging, particularly when clients present with multiple traumas, dissociation, shame, or complex maintaining processes.

Many therapists find it helpful to use structured formulation worksheets when developing a shared understanding of PTSD maintenance cycles. Psychology Tools offers a range of PTSD resources designed to support assessment, formulation and treatment planning.

Supportive resources like this can help therapists develop a shared understanding with clients and translate formulations into targeted interventions.

Practical Tips For PTSD Formulation

1. Keep early trauma descriptions brief

Clients do not need to recount every detail of the trauma during initial formulation work. Brief summaries are typically sufficient early in treatment.

2. Explore involuntary survival responses

Ask about freezing, dissociation, emotional numbing, or automatic bodily reactions that happened during the trauma. These experiences are often clinically significant. Many clients find it helpful to understand their experiences in the context of Schauer & Elbert’s (2010) ‘defence cascade’.

3. Identify hotspots

Explore which moments repeatedly return as flashbacks, nightmares, or intrusive memories. These are frequently good targets for trauma ‘reprocessing’ work.

4. Assess sensory qualities of trauma memories

Trauma memories are frequently sensory. Ask about sounds, smells, physical sensations, tastes, or visual images associated with the trauma.

5. Separate “then” from “now” appraisals

The model proposes that appraisals can drive a current sense of threat. It is helpful to differentiate thoughts experienced during the trauma from beliefs that developed afterwards as they often require different forms of intervention. For example, thoughts such as “I’m going to die” might be addressed during memory reprocessing, whereas it might be necessary to address thoughts such as “I’m permanently damaged” separately from memory work.

6. Explore shame and self-blame

Research indicates that internally directed appraisals, such as “I’m disgusting” or “it was my fault”, can strongly maintain PTSD symptoms.

7. Normalize coping responses

Avoidance, distraction, and suppression are often understandable attempts to cope with overwhelming distress. Formulation can be used to explore short-term and long-term consequences of these strategies: many lead to short-term reductions in distress, but have the unintended effect of leaving trauma memories unprocessed or unhelpful appraisals not addressed.

Clinical Implications

Trauma-focused cognitive therapy for PTSD (CT-PTSD) is recommended as a first-line treatment in multiple international guidelines, including those from the APA, ISTSS, and NICE.

Wild et al. (2020) describe three primary goals of CT-PTSD:

1. Elaborating and updating trauma memories

2. Modifying negative appraisals

3. Changing maintaining strategies while helping clients reclaim meaningful activities

A well-developed PTSD formulation provides the foundation for all three tasks. It helps therapists identify what maintains symptoms, guides intervention planning, and offers clients a compassionate and understandable explanation for their ongoing difficulties.

By helping clients understand why symptoms persist in the present despite the trauma being in the past, formulation provides a bridge between assessment and effective treatment.

Looking for practical PTSD formulation tools? Psychology Tools provides evidence-based worksheets, formulation templates, and treatment materials that are designed to help therapists apply cognitive models of PTSD in clinical practice.

Explore our PTSD resource library to support assessment, formulation and treatment planning.

References

• American Psychological Association. (2017). Clinical practice guideline for the treatment of posttraumatic stress disorder (PTSD) in adults.

• Brewin, C. R. (2014). Episodic memory, perceptual memory, and their interaction: foundations for a theory of posttraumatic stress disorder. Psychological Bulletin, 140(1), 69.

• Brewin, C. R. (2015). Re-experiencing traumatic events in PTSD: New avenues in research on intrusive memories and flashbacks. European Journal of Psychotraumatology, 6(1), 27180.

• Ehlers, A., & Clark, D. M. (2000). A cognitive model of posttraumatic stress disorder. Behaviour Research and Therapy, 38(4), 319–345.

• International Society of Traumatic Stress Studies. (2019). Posttraumatic stress disorder prevention and treatment guidelines.

• Kilpatrick, D. G., Resnick, H. S., Milanak, M. E., Miller, M. W., Keyes, K. M., & Friedman, M. J. (2013). National estimates of exposure to traumatic events and PTSD prevalence using DSM-IV and DSM-5 criteria. Journal of Traumatic Stress, 26(5), 537–547.

• National Institute for Health and Clinical Excellence. (2018). Posttraumatic stress disorder.

• Schauer, M., & Elbert, T. (2010). Dissociation Following Traumatic Stress. Journal of Psychology, 218(2).

• Wild, J., Warnock-Parkes, E., Murray, H., Kerr, A., Thew, G., Grey, N., … & Ehlers, A. (2020). Treating posttraumatic stress disorder remotely with cognitive therapy for PTSD. European Journal of Psychotraumatology, 11(1), 1785818.