Curious to know what the recent ISTSS conference was all about? Many thanks to Yoki Mertens for this reflection on the meeting! 

It is early morning in a freezing-cold Boston and Judith Herman presents as the first keynote speaker of the 35^th Annual Meeting of the International Society of Traumatic Stress Studies (ISTSS). One might assume the organizers scheduled it this way to ensure everybody arrives on time and it worked: The room is filled with over 1,700 attendees, more than ever before. It’s been 27 years since Judith Herman published her renowned book “Trauma and Recovery” and introduced the concept of complex PTSD. Back then, the New York Times called it “one of the most important psychiatric works to be published since Freud”.

The prevailing question of this annual meeting is: How far has trauma research, trauma therapy, and policies come in helping individuals with (complex) PTSD recover in the past decades? And which paths to take to move forward? After three days of attending symposia, panels, and poster sessions, it can be convincingly stated that steep progress has been made. Meanwhile, some challenges are left to be solved for the current generation of trauma researchers and clinicians.

Complex PTSD – The new/old kid in town

One of the big success stories discussed at the conference is the inclusion of the diagnosis Complex PTSD in the International Classification System (ICD-11).

Most attendees agree that inclusion of the additional disorder a) allows for more accurate diagnostics for those suffering from severe trauma-related symptomatology without a direct cause-effect relation and temporal proximity to the traumatic incident, and b) finally acknowledges the negative sequelae of chronic trauma exposure (in childhood) in the new classification system.

Network and latent class analyses are supportive that PTSD and the three additional complex PTSD criteria (affect dysregulation, negative self-concept, and interpersonal problems) indeed depict distinct network clusters and latent profiles, and can be clearly distinguished from borderline personality disorder (Philip Hyland).

Despite these positive developments, Herman emphasized in her keynote that in terms of prevention and healing, the numbers do not look too promising. Rates of rape incidents have not changed in the past 30 years and there is still a gap to overcome on societal and institutional levels between the victim, suffering from condemned isolation, and the bystanders.

Biomarkers on the rise

What has our increased biological knowledge brought us? Can biomarkers be used as risk factors of early life adversity or predictors for treatment outcome? A two-part panel and several symposia with the current experts of the field covered the most recent findings on genetics, epigenetics, psychophysiology, neurobiology, the neuroendocrine system, i.e. a systems biology approach.

The overall consensus was that biological markers are very useful and can contain high predictive power (think precision medicine) once we can integrate them into a coherent, multivariate model. This still remains a challenge.

A more controversial point made by Rachel Yehuda was: What to do when clinical data and biomarkers tell a different story? For instance, who should we trust when a patient does not report symptom reductions on self-report scales but shows clear improvements in fear inhibition measured by the startle response, as shown in research of for instance Tania Jovanovic?

Following their rationale, self-report should not be always the first choice since these questionnaires often require high levels of introspection (Yehuda: “We are asking a lot from patients to describe their own state”) and are sensitive to expectancy biases and socially desirable answers.

Treatment of Choice

So, what about the current state of trauma therapy? Certainly, there is no lack of evidence-based treatment options available for PTSD. Trauma-focused treatments appear to be effective for complex PTSD patients, but severe childhood maltreatment moderates this effect (Thanos Karatzias, Marylene Cloitre). For these patients, more specialized treatment forms, e.g. with increased focus on self-compassion and dissociative symptoms, should be further examined.

Prolonged Exposure (PE) and Cognitive Processing Therapy (CPT) received most praise for their impressive effect sizes across various modalities (e.g. successful transition towards CPT as e-mental health intervention). Online interventions have been also found helpful for patients suffering from more severe dissociative symptomatology (Bethany Brandt) and in reaching discarded, traumatized communities in low-income countries, as demonstrated in global mental health interventions (Theresa Betancourt).

Meanwhile, futuristic-looking, innovative adaptations of existing treatments such as 3MDR, where EMDR techniques are implemented in a virtual 3D space, still need to withstand the test of time, but show promise in facilitating trauma processing in treatment-resistant patients (Marieke van Gelderen, Mirjam Nijdam, Eric Vermetten).

When I had the chance to ask Patricia Resick, inventor of CPT and recipient of this year’s lifetime achievement award, at the ISTSS Student Lunch on her opinion regarding current trends towards transdiagnostic treatment approaches such as Process-based CBT (see Stefan Hofman’s work), her response was rather skeptical. There is no evidence yet that focusing on transdiagnostic processes, e.g. repetitive negative thinking, is equally or more beneficial compared to targeting PTSD-specific symptom patterns. Then again, Herman, supported by several audience members, urged not to forget the crucial role played by strong therapeutic alliance.

2019 ISTSS President Julian Ford said:

“We need to understand that restructuring and exposure is basically a shift from the framework of external coercion to self-directed self-efficacy. What does it mean to be self-directed? It means you make your own choices, it means that you have control of your life. External coercion is in the heart of tyranny (..). It creates an internal sense of turmoil and sense of never being safe, that’s hypervigilance. I think that is what drives intrusive memories, flashbacks and avoidance. because if you never feel save, you try to avoid. The more you avoid, you think about what you try to avoid, and remember things you do not want to remember, and feel what you do not want to feel. That’s the trap called post-traumatic stress. So, when we do our treatments we should be very thoughtful about how we are actually helping people to regain the ability to intentionally make their own choices.”

Trustworthy Algorithms?!

Another exciting venture for the future is the proposed fusion of machine learning techniques and trauma research. Most agree that the construct of PTSD is inherently problematic considering high heterogeneity (see also 636,120 ways to have post-traumatic stress disorder) and the multifinality of trauma.

In Yehuda’s words, if we want to measure the full impact of traumatic life incidents we need to study “the good, the bad, and the ugly”. Thus, a comprehensive prediction model should include both risk markers and protective factors (resilience), and meanwhile acknowledge the complex interrelationships across biological and environmental influences and high correlation among trauma-related symptomatology.

Such a model requires many data points collected at different times, include large set of potential predictors/outcomes, and an unbiased view on which factors relate to or predict each other. If the thought itself of how this model would look in reality seems overwhelming, you are not alone. Algorithmic machine learning can help us to disentangle this complexity and potentially bring more objectivity into our clinical discussion.

For instance, a new algorithm on trauma-related diagnoses clearly showed in two distinct samples that PTSD causally predicted depressive symptoms, not vice versa (Sisi Ma). As algorithms do neither follow a priori defined hypotheses, nor are tied to specific theoretical models, this is certainly a path worth exploring to inform data-driven prediction models (see this overview of machine learning and PTSD).

Final reflections

Being a first-time attendee at a trauma conference of such a scale can feel intimidating at first, but looking back it was definitely worth the long journey. Besides listening to the extensive program and learning from the long list of experts in the field, ISTSS is a great place for networking. As such, I had the honor to discuss my research with Bessel van der Kolk and Scott Orr, who curiously attended the poster sessions and asked questions to researchers in their early career.

On a more critical note, several attendees outside the U.S. mentioned the bias towards exclusively America-centralized ideas on policies and funding and wished for more global representation of the trauma network.

Miriam Lommen and Joanne Mouthaan, the organizers of the European STSS (ESTSS) conference say:

“Because we know how much effort goes into the organization of a congress, special thanks to the organizing committee for their great work. Initial steps were already taken during the ESTSS congress in Rotterdam to enable closer collaborations of the trauma organizations. It important to look ahead in which areas we can collaborate even more. We are happy to play a role in strengthening the cooperation between the European (ESTSS) and international association (ISTSS). Ultimately, we work in the same field and would benefit from informing and learning from each other. The message is global! ”

Another observation made was the lack of discussion on symposia or panels. To be fair, these debates were likely happening off-stage in-between the talks or at the reception after a glass of wine. However, for a true critical scientific reflection, a respectful, yet passionate debate of opposing ideas on which path to follow and which trends to politely dismiss, I can imagine more people would be interested in listening to and learning from. While there is so much (necessary!) talk on consent and bridging the gap between victims and bystanders, individual and community-based interventions, trauma researchers and clinicians, clinicians and politicians, etc., I would like to encourage more integration of constructive difference into the current scientific debate on traumatic stress.

Written by Yoki L. Mertens, PhD Student, University of Groningen. Edited by Joanne Mouthaan, Assistant Professor, University of Leiden. Thanks both!