The majority of our current work falls under these three research themes. We take a collaborative, team-based approach to science and welcome new partnerships at the intersection of trauma, neuroscience, and public health. Contact us to explore opportunities to work together!

Identifying Early Biomarkers of PTSD

We identify early brain- and blood-based markers of PTSD following traumatic events such as motor vehicle collisions, physical assaults, and natural disasters.

PTSD is marked by dysfunction within threat circuitry, including the prefrontal cortex, hippocampus, and amygdala; however, our work highlights alterations in regions beyond this canonical circuitry, including smaller structures probed in preclinical models, such as the periaqueductal gray, that may predict PTSD (e.g., Webb et al., 2020). Further, we have demonstrated that machine learning approaches, such as multivoxel pattern analysis (MVPA), can identify novel whole-brain patterns that predict PTSD risk in the early aftermath of trauma (Fitzgerald and Webb et al., 2022). 

The predictive value of PTSD biomarkers differs by ethnoracial group and gender. Marginalized groups (e.g., women, Black Americans) experience more chronic and severe PTSD, driven by trauma and adverse life experiences. For example, lifetime racial discrimination predicts acute stress responses and future PTSD in Black survivors (Bird and Webb et al., 2021), is associated with greater connectivity between threat-detection regions (e.g., amygdala and insula; Webb and Bird et al., 2021), and modifies how well individual differences in resting-state patterns of the brain predict PTSD (Petranu and Webb et al., 2024).

Contributions of Environmental Exposures on PTSD Risk

We investigate how environmental exposures—including air pollution, extreme heat, neighborhood disadvantage, and greenspace—shape biological responses to trauma and influence the risk of developing PTSD.

Historically, approaches to understanding PTSD development have focused largely on individual factors and often overlooked key socioenvironmental factors. Dr. Webb's early work provided initial evidence that neighborhood disadvantage is associated with altered structure and function of regions implicated in PTSD (Webb et al., 2021). More recent work suggests that neighborhood disadvantage influences neural responses to uncertain or unpredictable threats (Tomas and Webb et al., 2022).

As a postdoctoral fellow, Dr. Webb examined how neighborhood disadvantage affects neural processing of threat and reward in the largest prospective study of recent trauma survivors to date. Greater neighborhood disadvantage was linked to altered threat reactivity in the insula and anterior cingulate cortex, with effects partially mediated by alterations to white matter microstructure (Webb et al., 2023).

Over the past few years, we have investigated how extreme heat and air pollutants may increase neurobiological susceptibility to PTSD in the United States and South Africa. Even in neighborhoods with levels of air pollutants below the EPA guidelines, greater exposure to pollution is associated with more severe PTSD symptoms. Ultimately, this core line of research underscores the critical need to understand how socioenvironmental stressors become biologically embedded, with direct implications for improving early identification of trauma survivors at risk for PTSD.

Mechanisms of Resilience

We investigate the individual, environmental, and biological factors that may promote resilience and recovery after trauma.

Focusing on resilience allows us to identify where to focus resources to enhance the effectiveness of treatments and interventions. For example, Dr. Webb's research demonstrated that trauma survivors with both higher green space exposure and greater personal psychological resources demonstrate better psychological recovery after trauma. Further, greater exposure to residential green space is associated with greater brain reactivity to reward following trauma (Webb et al., 2024). 

Our ongoing work investigates which resilience factors are most effective in different contexts. While protective factors can support psychological recovery, their impact on biological outcomes is less well understood. For instance, we demonstrated that higher self-reported psychological resources may buffer the effects of neighborhood disadvantage on biological aging (Webb et al., 2026). 

Overall, this line of work attempts to identify resilience factors and determine how they operate across different circumstances to support recovery.