How to depict multiple personality disorder?

So first the person must have one dominant personality and functions well and is noted by their behavior and actions as normal. The person at first can have a dominant or also a submissive behaviour, you like two twins, the good twin, and the bad twin. Either can be explained by being possessed, or mentally ill or a trauma that brought this behavior to the individual. Also when the other personality takes old, the other it is possible has no idea what took place, what was said or what took place.

I'd say do a lot of psychology research. 

I've known of a couple of people with the disorder. This is of my experiences with them and self research, so I can't say it's the same for others.

From what I know. Multiple personalities are typically triggered by extreme mental and physical circumstances that has been happening for years. At least of the people I know. To reduce the personalities to one would take a lot of therapy and having the person be in a trusted relationship and safe environment for almost double the length of time as the period of abuse. They may need to be on a medication plan for biploar disorder and similar, since their bodies would have likely gone through the mill with the constant switching of moods and mannerisms. They may also have no memories of the other persona, since they're a separate, different person. Unless they all talk to each other. But, they'll all consider themselves separate entities, so they'll only know external experiences.  

For the other person being the friend. It can tax a lot on the mind, body and soul. Since they always need to be ready to adjust their approach to suit the personality.  It takes an extremely selfless, patient and calm person to be able to be by their side(s) for as long as possible. Especially if one of the personas doesn't like the friend.

One thing I've always felt that was a common need for the triggers. Escape. I can't really say if that's the case since I don't suffer the disorder. It almost feels to me that the person is feeling so helpless they need to find a way out. That may mean creating their own hero to help themselves escape their abusive situation or cope with their life trauma.

Again, this is just from my perspective.

Posted by: @veronica

I'd say do a lot of psychology research. 

I've known of a couple of people with the disorder. This is of my experiences with them and self research, so I can't say it's the same for others.

From what I know. Multiple personalities are typically triggered by extreme mental and physical circumstances that has been happening for years. At least of the people I know. To reduce the personalities to one would take a lot of therapy and having the person be in a trusted relationship and safe environment for almost double the length of time as the period of abuse. They may need to be on a medication plan for biploar disorder and similar, since their bodies would have likely gone through the mill with the constant switching of moods and mannerisms. They may also have no memories of the other persona, since they're a separate, different person. Unless they all talk to each other. But, they'll all consider themselves separate entities, so they'll only know external experiences.  

For the other person being the friend. It can tax a lot on the mind, body and soul. Since they always need to be ready to adjust their approach to suit the personality.  It takes an extremely selfless, patient and calm person to be able to be by their side(s) for as long as possible. Especially if one of the personas doesn't like the friend.

One thing I've always felt that was a common need for the triggers. Escape. I can't really say if that's the case since I don't suffer the disorder. It almost feels to me that the person is feeling so helpless they need to find a way out. That may mean creating their own hero to help themselves escape their abusive situation or cope with their life trauma.

Again, this is just from my perspective.

This information and experience would be really helpful. Thanks for sharing it. I had done some research but I wasn't sure if I will be able to effectively express it. I agree that the role of therapy and family/friends will be quite important for them so, I would also be touching on those topics.

As mentioned earlier, you need to do a lot of research to dive deep into the character. Then, you need to observe from a neutral perspective and write about the character. I would also suggest you to read about the experiences of therapists as it would help you with the content.

Would be nice to read some case studies about this and see how people suffering from it behave. 

The move "Split" may be an extreme version of this.

Posted by: @junamo

Would be nice to read some case studies about this and see how people suffering from it behave. 

The move "Split" may be an extreme version of this.

I got this idea of writing about multiple personality disorder after watching the movie Split. I think the actor switched between different characters with perfection. However, I also wanted to know about other factors involved in it and how to make the audience believe in the 'switch'. Yes, I would be referring to case studies to know about the experiences of different patients.

@i-write Yes! James McAvoy was Phenomenal. Good luck with your research.