Three characters, three life stories, integrate as a schizophrenic detective puts together puzzle-pieces in a quest to imprison a split-serial killer posing as Hollywood’s Messiah. — WHOLE

Uhum. Sound like it fits. And because some symptoms are similar, as you mentioned, I can see him thinking Schizophrenia until he learns more. Cool!

I was going for both. See my original logline we are discussing here. I did some extra research. You can't be Schiz.and MPD (these days called DID) at the same time . It is one or the other The main condition of the lead and its alter ego's of course is MPD (split). But he also has symptoms you see in both mental conditions. And that is possible. Here I want to use forgetfulness, sleeplessness, and being confused. Interesting is that even the "host" Character doesn't know that there are other alter egos. I think I make the "host" character the person standing in between the detective and the killer, But only the killer knows, or maybe feels there are other alter egos like him, and one of them is the detective. Also interesting is that it can take minutes, hours OR days before there is a switch from one alter ego to another, Of course, I will use 'days'. Being the only way of setting up three characters=ater egos having their own lives apart from each other, all the (or more) living in their own neighborhood, different house.

It could feel like the MPD is somewhat theoretical because the alter egos (except the killer) do not know that there are OTHER alter egos. What all three (maybe more) alter egos do know about themselves is that they feel confused, have memory loss and always feel tired.

About the "flashes". Yes that is part of the style that should be used. All have flashes. And yes focussing on the lead, being the detective, he becomes more spooked and unsure along the way because of his "flashes", but those "flashes" of course are puzzle peaces much needed to completing the puzzle.

Thanks, man, Richiev, Odie, and you helped me a lot.

So because MPD almost always caused by a trauma in early childhood, causing it by a car accident where he drives and loses his parent is not possible. What is possible is him distracting his father when he drives being the reason for the fatal exident.

Seems to me, that you mc has two conditions . The MPD and the schiz. Could the schiz be caused by the mod? Maybe. I think MPD is at this stage somewhat theoretical. You may have some freedom in how to interpret it. Eg. your mc remembering flashes from one of his alters. Then he thinks he’s developing schizophrenia.... 🤔
Is that what you were going for?