Read Full Story Karestan Koenen, professor of psychiatric epidemiology at Harvard Chan School, is an expert on post-traumatic stress disorder (PTSD), a psychological reaction that occurs after a high-stress event and includes symptoms such as depression, anxiety, and flashbacks. Here, Koenen discusses PTSD among victims of sexual violence—and how to address the problem.Usually we hear about PTSD among soldiers returning from war, or people who have lived through disasters. Is it also common among victims of sexual violence?It’s very common. We do studies that look at PTSD in the general population, through which we can link PTSD to different kinds of events. We find that most PTSD in the U.S. population—close to 50%—is due to sexual or physical violence. That includes rape and sexual assault, but also partner violence, mugging, and childhood physical and sexual abuse. Around 30% of PTSD is due to sexual violence alone.When people are shown how common these types of things are, they are often surprised. Part of the problem is that people who’ve had these experiences don’t share them because there’s a lot of stigma associated with them. So that adds to the perception that they don’t happen that often.Most victims of sexual violence are women. Among women who are raped, about 50% will develop PTSD. All of those women will initially have PTSD symptoms, but about half will recover. About a quarter of women who are raped may have symptoms that don’t lessen over time.