Critical Analysis of “Pre-trauma Individual Differences in Extinction Learning Predict Posttraumatic Stress”

The study conducted by Miriam Lomen, Iris Engelhard, Marit Sijbrandi, Marcel van den Hout, and Dirk Kermans reports findings that one of the causes for the development of posttraumatic stress disorder (PTSD) could be reduced extinction learning. PTSD is a disorder that many patients suffer after a traumatic experience, such as a car accident, fire, rape, or active military combat. Extinction learning refers to the phenomena of a conditioned response (also known as a learned response) that gradually fades or weakens over time, such as someone overcoming a food aversion by continually eating that food. The food aversion would become extinct as a result of the activity of continually eating that particular food. The study by Lomen et al. administered a test to “assess individual differences in extinction learning” among soldiers from the Netherlands (Lomen at al. 2013, 63). The conditioned response being tested was fear, and the researchers wanted to test results based on the fact that, “Studies using the ‘de novo’ conditioning paradigm have found that participants with PTSD show delayed fear extinction, compared to control groups with and without trauma exposure” (64).

The study methods included administering a pre-test to soldiers and a post-test following a several-month deployment to Afghanistan and surrounding areas. Results from the study show, “reduced fear extinction before deployment predicted subsequent PTSD symptom severity, over and beyond degree of pre-deployment stress symptoms, neuroticism, and exposure to stressors on deployment” (66). This means that the researchers found stronger correlation with the indicator of extinction learning than with other stress symptoms. Continued research in this field may result in better ranking and weighting of the factors and preconditions that could lead to PTSD onset.

As for limitations within the article, there are a few minor issues, beginning with experimental design based on what the article states early: “Since the majority of studies assessed ‘pre-trauma’ factors retrospectively, contamination with current posttraumatic distress may not be ruled out” (63). This is not just a limitation with the study but within the field, so it does not detract from this paper’s credibility in comparison to like papers. However, it does signal an issue within the field, which is to say that uncorrupted data is difficult to capture at present. Therefore, the conclusions researchers are drawing upon in isolating a potential factor in the development of PTSD, namely the levels of extinction learning, could be intermingled with other factors that have not been identified or isolated.

Another limitation is the lack of cultural diversity and career diversity, creating a homogeneous sample. By only using soldiers form the Netherlands, the researchers’ findings might be influenced by cultural bias as well as a predilection for one career choice (military). People who would not opt into military service may well have a different response to the tests as conducted. A final limitation is that the severity of traumatic stressors in this case are exceptional. Being shot at, witnessing explosions, and so on are extreme levels of stress, and so some accounting of how much stress certain stressors produce needs to be addressed.

A final limitation is the practical implication for this particular research study. It is easy to identify certain groups as being likely candidates for possible traumatic experiences, including soldiers and first responders to accidents and disasters, but for the rest of the population, such identification is difficult or irrelevant. Millions of people in the United Kingdom do not need such assessment, and therefore the application of the study at present, while non-intrusive, is not wholly necessary to the public.

Yet there are some interesting implications for this work, and it sparks interest in pursuing the feasibility of pre-testing candidates for professions in which trauma is expected to be present, including those mentioned earlier—firefighters, police officers, and other emergency personnel who respond first to disasters; soldiers; and workers in industries with above-average hazards, such as mining, deep sea salvage, and so forth. If indicators for a predisposition to PTSD can be determined in a non-invasive pre-test that can be incorporated in the screening, selection and evaluation processes of recruits or job candidates, then resources may be allocated to helping those individuals build coping strategies or find access to care and resources that can treat PTSD.

Likewise, if more indicators such as levels of extinction learning can be isolated and identified as causal or correlative to a predisposition for diagnosing  PTSD after exposure to a traumatic event, then educators, therapists and clinicians can develop learning models and exercises to help people develop the habits and conditioning needed to produce adequate coping mechanisms and possibly prevent the onset of or dilute the severity of posttraumatic stress disorder after exposure to traumatic situations and events.

Consider hypothetically that military conflict between nations increases as a result of water or petroleum shortages. In the event of a national draft, a psychological examination that determines if a candidate is predisposed to PTSD may help military personnel effectively assign recruited soldiers to areas within the military where exposure to trauma is directly related to their predisposition to develop PTSD or an assessment of their coping skills warrants such placement. A greater increase in overall mental health and a decrease in the financial and other resources required to treat mental health issues occurring after military service could be a primary result of such pre-screening.

Reference

Lomen, M., Engelhard I., Sijbrandij M., van den Hout, M. and Hermans, D. (2013). “Pre-trauma individual differences in extinction learning predict posttraumatic stress.” Behaviour Research and Therapy, 51, 63–67.