John Medina, PhD

This is the last installment in a 3-part series discussing the behavioral, cellular, and molecular characteristics of posttraumatic stress disorder (PTSD). In Part 1, I described some basic clinical observations of PTSD and the challenges these observations pose to researchers attempting to understand underlying biological substrates.1 Part 2 examined progress on addressing these challenges at the level of the tissue and cell.2 In Part 3, I will discuss efforts to understand PTSD at the level of DNA, including potential genetic underpinnings and heritable risk factors.