Hey, awesome person! Thanks for reading, I really appreciate it :) I think the following passage will answer some of your possible questions, but if you are still uncertain about anything, feel free to ask!

Multiple personality disorder (MPD) is a psychiatric disorder characterized by having at least one “alter” personality that controls behaviour. The “alters” are said to occur spontaneously and involuntarily, and function more or less independently of each other. Amount of “alters” varies depending on individuals. Memory and other aspects of consciousness by which we identify ourselves are said to be divided up among “alters” in the MPD. Another symptom of MPD is significant amnesia (memory loss), which can't be explained by ordinary forgetfulness. MPD is an effect of severe trauma during early childhood, usually extreme and repetitive physical, ual or emotional abuse.