According to research; anxiety, depression, disassociation, depersonalization, panic attacks, frequent flashbacks, nightmares, and emotional distress are all common in patients with PTSD.
Disassociation is when thoughts or emotions enter your mind and you find yourself incapable of focusing on your actions, instead operating on autopilot or watching yourself do things without feeling connected to your body.
So, I'm going to show you a couple of clips that illustrate the disassociation from " Memento." Those of you who have seen the movie know that this ends up quite tragically for Sammy.