Rapid brain responses to affective pictures indicate dimensions of trauma-related psychopathology in adolescents

Case-by-case: neural markers of emotion and task stimulus significance

The present study assessed the hypothesis that electrophysiological markers of emotional and task stimulus significance can be demonstrated in concert at the level of the individual case. Participants (n = 18, 9 females) viewed low and high-arousing pictures selected from behavior systems of sexual reproduction, disease avoidance, and predator fear. Furthermore, to concurrently manipulate task relevance, participants performed an explicit emotion categorization task with either low or high-arousing pictures alternating as target stimuli in separate experimental blocks. Pooled across behavior systems, event-related components sensitive to emotional significance reached statistical significance in 100% of the tests for the early posterior negativity and in 96% of the tests for the late positive potential. Regarding explicit task relevance, the target P3 effect was significant in 96% of the tests. These findings demonstrate that neural markers of stimulus significance driven by emotional picture content and explicit task demands can be assessed at the individual level. Replicating an effect case-after-case provides strong support for an effect common-to-all and may support individual inferences. Contributions of the case-by-case approach to reveal reproducible effects and implications for the development of neural biomarkers for specific affective and cognitive component processes are discussed.

Trajectories of posttraumatic stress symptoms during and after Narrative Exposure Therapy (NET) in refugees

BACKGROUND

Trauma-focused therapy approaches are recommended as treatment for posttraumatic stress disorder (PTSD). This includes the treatment of trauma-related suffering in refugee populations. However, there is a lack of knowledge about symptom trajectories in refugees living in volatile conditions. This has led to fear of "retraumatisation" and general skepticism in clinicians concerning the use of exposure therapy.

METHODS

To test the relevance of this concern, we investigated PTSD symptom trajectories and potentially influencing factors during the course of Narrative Exposure Therapy (NET) in a refugee sample living in Germany. Refugees filled out the PTSD Checklist prior to each treatment session and also during follow-up interviews. Therapists continuously documented positive and negative life events as well as the content of the treatment sessions. Additionally, structured clinical interviews were conducted pre-treatment and at follow-up time points.

RESULTS

On average, clients presented with substantial decreases in PTSD symptoms already during and after NET. However, symptom trajectories differed and ranged from fast responders to slow responders to no immediate response during treatment. Importantly, a persistent worsening of symptoms was not observed, also not after exposure to the most distressing events. In contrast, stressful life experiences seemed to aggravate PTSD symptoms.

CONCLUSIONS

Consistent with earlier studies, NET leads to clinically and behaviorally relevant reductions in PTSD symptoms both throughout and following treatment in refugees living in volatile conditions. Concerns about imaginal exposure in refugees were not substantiated. While stressful life events contributed to transient symptom increases, they weren't found to prevent the overall effectiveness of NET.

TRIAL REGISTRATION

NCT02852616.

Rapid brain responses to affective pictures indicate dimensions of trauma-related psychopathology in adolescents

A variety of mental disorders are related to deviant brain activity, but these neural alterations do not validate psychiatric diagnostic categories. High symptom overlap and variable symptom patterns encourage a dimensional approach. Following the logic of the Research Domain Criteria (RDoC), we investigated trauma survivors for symptom clusters that might be associated with characteristics of ERPs, in particular with the early posterior negativity (EPN) elicited during affective picture processing. In rapid serial visual presentation, 90 adolescents (40 male/50 female, age M = 15.0 ± 2.5 years) who had been exposed to varying amounts of traumatic stress passively viewed a stream of high‐arousing positive and low‐arousing neutral pictures taken from the International Affective Picture System (IAPS). Using standardized interviews, symptoms of trauma‐related mental disorders were assessed (including those for PTSD, depression, borderline personality disorder, and behavioral problems). A principal component analysis was performed to derive potential dimensions of psychopathology. Multiple regression analysis confirmed a factor comprising problems concentrating, sleeping difficulties, and mistrust as a predictor of a larger EPN difference between high‐arousing positive and low‐arousing neutral IAPS pictures (β = 0.19, p < 0.05). Sex predicted the magnitude of the EPN (β = 0.45, p < 0.001). Male adolescents displayed a stronger EPN suppression than female adolescents. The result suggests that problems concentrating, sleeping difficulties, and mistrust seem to be trans‐diagnostic elements related to diminished early emotional discrimination represented by the EPN. Furthermore, our findings indicate that the EPN in response to emotional processing is modulated by sex.

Based on the RDoC heuristic, symptom clusters that may be associated with the early posterior negativity (EPN) elicited during affective picture processing were investigated in youth trauma survivors. Analysis confirmed a factor comprising problems concentrating, sleeping difficulties, and mistrust as a predictor of a larger EPN difference between high arousing positive and low arousing neutral IAPS pictures using rapid serial visual presentation (RSVP). The EPN component was also modulated by sex. The findings also extend those of prior research on emotional processing confirming that EPN suppression can also be found in adolescents.