Truddi's therapist, Dr. Robert Phillips, says what causes a personality split like Truddi's is unclear. "It seems to be something about the brain, about the mind, which allows this very creative process to come in and to help defend a person. It usually is a person who is abused very, very young—before personality is formed," he says. "When you're so young everything is overwhelming; the whole world is overwhelming. Something like this just overloads, so the person cannot stay there and take it."
Dr. Phillips says despite Truddi's condition, he doesn't like calling her "dysfunctional." "It's the most functional way to help a child survive. A child does not die but is able to survive and goes on," he says. "Many, many people who are multiple function quite well. I've worked with a man who is a lawyer. I've worked with people who are professionals, counselors, medical doctors. They are able to go on and live life."