Different personalities may act like they have different ages, genders, or races. There may be as few as two identities or more than one hundred. The personalities may or may not have knowledge of the others. Stress tends to bring on changes in personalities. The cause of this disorder remains unknown.
Some professionals believe it is related to severe physical or sexual abuse in childhood.
Many people with dissociative identity disorder also have depression, sexual disorders, eating disorders, or sleep disorders. Many have post-traumatic stress disorder. This disorder appears to be more common in females than in males. There has been a sharp rise in reported cases in recent years. Individuals who are highly suggestible may be misdiagnosed.