Genetic Influences on PTSD

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Post-traumatic stress disorder (PTSD) is a neuropsychiatric disorder triggered by experiencing or witnessing a traumatic or terrifying event. Currently, there are few studies related to PTSD, especially few specifically investigating how stressors from the environment can change and impact gene expression related to PTSD. Previously, researchers tended to focus on blood biomarkers. However, this approach does not address the neurological nature of the disorder. “Blood is a peripheral tissue that is not necessarily indicative of what’s going on in the brain,” said Carina Seah, an MD-PhD student at the Icahn School of Medicine at Mount Sinai. Instead, Seah and a multi-institutional team looked at skin biopsies. They collected connective tissue cells from forty veterans’ skin and reprogrammed the cells into neurons using novel stem cell technology while retaining the genetic information the cell donor had. “We can watch the entire disease model with a stem cell model… Stem cells are kind of like these amazing bridges that can connect fields,” said Kristen Brennand, Professor of Psychiatry at the Yale School of Medicine. 

They conducted the study at the height of the COVID-19 pandemic, so an innovative work setting had to be adapted, including coordinated zoom calls and scheduled wet laboratory shifts. This study also connected a diverse array of expertise with collaboration between three different laboratories and the New York Stem Cell Foundation. “It was definitely a great testament to establishing cross-expertise environments,” said Seah. Since it was the first study to use induced pluripotent stem cells in PTSD, their results were groundbreaking—the study demonstrated there is likely a genetic factor interacting with the environment which, in the future, could better predict who will develop PTSD.

 “I hope those who read our paper learn the importance of considering the environment when we talk about psychiatric disorders,” said Seah. By studying gene expression, the researchers demonstrated how the human gene sequence could respond to external stressors. “On average it takes ten years for someone to be treated once a psychiatric disorder is onset. If we could figure out how to tamp down that stress response, we could use this to both see who is at high risk and how to prevent PTSD”, said Brennand.