Post-traumatic stress disorder, commonly known by the acronym PTSD, is a psychological condition that often affects individuals following a traumatic experience. It comes in many varied forms and affects different people in different ways, but it usually has the central thread of a person reliving the event in their mind. This might come in the form of nightmares, obsessive memories, or heightened emotions triggered by anything the mind associates with the event. One doesn't even need to be on the receiving end of trauma to develop PTSD. Simply witnessing a traumatic event can be enough. PTSD can even develop in the minds of people who inflict trauma onto others. Because of this, PTSD is commonly associated with soldiers who, by the nature of their job, are subject to trauma both as perpetrators and victims. PTSD has affected people throughout history, although it is only recently that it has really started to gain recognition instead of being dismissed as mere cowardice.