Can PTSD occur months or years after trauma?

Is it possible for someone to develop symptoms of PTSD months or even years after experiencing a traumatic event, even if they seemed fine initially?

PTSD doesn’t always show up immediately. Months or even years after trauma, stress or certain triggers can bring symptoms out. I’ve personally seen a friend go from seeming fine to dealing with severe anxiety a year after a traumatic event, and therapy was a game-changer.