In this episode of The Biological Psychiatry Podcast, Dr. Elvisha Dhamala sits down with Dr. Nathaniel Harnett from McLean Hospital and Harvard Medical School to discuss his recent paper published in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging.

When we think about the neurobiology of PTSD, regions like the amygdala and prefrontal cortex typically come to mind. But an emerging body of research points to the visual cortex as potentially important for understanding trauma-related outcomes. A critical question, however, has remained unanswered: are changes in visual cortex structure a consequence of PTSD itself, or of trauma exposure more broadly? In this conversation, we explore how the team addressed this question by comparing cortical thickness of early visual areas in recently trauma-exposed individuals and controls across two independent samples. Dr. Harnett explains why distinguishing trauma-related from PTSD-specific brain changes matters for biomarker development, and what it means that primary visual cortex was thicker after trauma exposure independent of PTSD symptom severity. We also discuss what the regional specificity of these findings tells us about how trauma acutely impacts the brain, and why the absence of pre-trauma imaging remains one of the field's greatest challenges. The conversation closes with a look at what these findings mean for understanding the earliest neurobiological impacts of trauma and identifying who may be most vulnerable to developing PTSD.

Paper:

Recent Trauma Exposure Is Associated With Greater Thickness of the Primary Visual Cortex: A Discovery and Replication Analysis

DOI: 10.1016/j.bpsc.2026.04.016

Follow Biological Psychiatry:

Biological Psychiatry

Biological Psychiatry: Cognitive Neuroscience and Neuroimaging

Biological Psychiatry: Global Open Science

Instagram: @biologicalpsych

LinkedIn: Biological Psychiatry

Bluesky: Biological Psychiatry

This podcast is for informational purposes only and does not constitute medical or professional advice. The views expressed are those of the participants and do not necessarily reflect those of the Society of Biological Psychiatry, its family of journals, or its editors. © 2026 Society of Biological Psychiatry. All rights reserved, including those for text and data mining or use in AI systems.