Multiple Personalities Support Group
Dissociative identity disorder is a diagnosis described as the existence in an individual of two or more distinct identities or personalities, each with its own pattern of perceiving and interacting with the environment. At least two of these personalities are considered to routinely take control of the individual's behavior, and there is also some associated memory loss,...
As an adult, I have developed other alters when I've felt that same degree of stress (although not resulting from the same sorts of traumas).
In my experience, I get triggered by something and then feel traumatized - even if it's not traumatic for others. So, I create new people.
However, when it happens, I often feel off-kilter and may have gaps in my memory.
So, yes, I think it is possible. It's also possible to see it as positive, healthy adaptive behavior instead of a detriment or disability. From that stand-point, you can say "We need to gently exercise a bit, learn to eat healthier - is there anyone in the system who enjoys these things and can come forward to help us?"
Just that shift - from seeing multiplicity as a weakness to seeing it as a strength - can make a huge difference.