Physical activity moderates the relationship between PTSD symptom severity and approach-avoidance conflict decision-making

Abstract

Avoidance of potentially dangerous contexts is beneficial for survival (i.e., adaptive avoidance), but the generalization of avoidance behavior to other generally safe contexts (i.e., maladaptive avoidance) can lead to detrimental mental health consequences, including diminished potential for reward. Decisions around pursuing reward in the presence of threat or avoiding threat at the cost of obtaining greater reward presents an approach-avoidance conflict (AAC). Although AAC is expected to be biased among trauma-exposed adults, especially those with posttraumatic stress disorder (PTSD), there have only been two prior behavioral investigations of AAC among adults with PTSD or experiencing PTSD symptoms. While greater levels of physical activity (PA) contribute to enhanced cognitive performance during reward-based decision-making tasks, it remains unknown whether greater PA also offers a protective effect or rather dampens the potential for greater AAC and sacrifice of reward in the presence of threat. The current study administered a trauma-related AAC behavioral task to trauma-exposed adults with varying PTSD symptom severity (N = 93), to examine potential interactive relationships between PTSD symptom severity, PA, and AAC decision-making under threat. The task involved a total of 150 trials and was divided into two phases: congruent (the option with the highest probability of a positive point outcome was also the option that was least likely to result in the presentation of a trauma-related image), and conflict (the option with the highest probability of a positive point outcome was also the option that was most likely to result in the presentation of a threat-related image). Results from linear mixed effects models revealed that PA moderated the relationship between PTSD symptom severity and AAC, as we observed a positive relationship between PTSD symptom severity and AAC for lower PA volume (i.e., greater conflict), and a more negative relationship between PTSD symptom severity and AAC as PA volume increased (i.e., less conflict). These results suggest that greater PA may promote a greater propensity to engage in goal-directed behavior and seek reward in the presence of threat in those with greater PTSD symptom severity.