There is new evidence that a 50-year-old blood pressure drug could find new purpose as a treatment to mitigate PTSD, scientists say. Clonidine is commonly used as a high blood pressure medication and for ADHD. It's also already been studied in PTSD because clonidine works on adrenergic receptors in the brain, likely best known for their role in "fight or flight," a heightened state of response that helps keep us safe. These receptors are thought to be activated in PTSD and to have a role in consolidating a traumatic memory. Clonidine's sister drug guanfacine, which also activates these receptors, also...