My question would be, what is the dilemma everyone is suffering from with amnesia due to PTSD?
Is the main story you want to tell that everyone wants to remember but can’t remember? Don’t forget that whatever your story Goal is, it will also be the main dilemma that’s focused on in the story (the Concern) … i.e. Your acts will be like Act 1 is all about Impulses with an overall concern of Memory, then Act 2 is Conscious with an overall concern of Memory… and so forth.
If getting their Memory back would come from treatment, that seems to me like a Dividend rather than the bad thing that will happen–just based on getting back their memories as a form of healing.
Just talking about what a dilemma of Conceptualizing looks like whomever represents that perspective.