Boris Sidis, a psychiatrist and psychologist, tried to define the concept of personality and its composition by defining the personality and what it consists of. He began by presenting some of the cases that were studied and diagnosed with multiple personality disorder, specifically the case of "Hannah," which was studied in depth about trying to blend all the personalities to their first state through a deep hypnosis experience to discover who is the stronger personality! .. He also did not stop at presenting this case, as he presented other interesting cases for study in cases of multiple personalities in psychiatry, which will make you stand amazed at what a single human soul endures due to being afflicted with multiple personalities. These cases are not a figment of the imagination, but rather they are from the reality of psychological and medical files.