Humans are ingenious. We’ve cured the likes of polio, measles, rubella, and smallpox with vaccines after years of research. So why can’t we cure posttraumatic stress disorder (PTSD)? The answer is complicated because, as with all mental health disorders, PTSD has mysterious causes and so far, only some of its symptoms can be managed. The goal of treating PTSD is to allow – through therapy, education, medicine – affected individuals to return to some level of normalcy.