Multiple personality disorder Multiple personality disorder , also known as a split personality or a dual personality , was a mental illness in which a being would develop one or more separate identities in addition to their original personality . These personality states would recurrently take control of that being ' s behavior , and would differ from the host personality in characteristics and mannerisms . Sometimes , the traits of an alter would be modeled after that of another individual ' s personality . The host may or may not be aware of the alternate personalities , and likewise for the alters to be aware of the host , though the personality states could enter into conflict with each other . The condition typically would arise from periods of severe stress or psychological trauma and could affect Gands and Humans in varying severity . Characteristics . Multiple personality disorder was a mental condition that was characterized by two or more distinct personality states . These alternate personalities would normally develop in times of severe stress or emotional trauma , and would often differ drastically from the host personality , and sometimes may even be of a different gender . The affected individual would not be aware of their alternate personalities , likewise for the alters to be unaware of the host . The personalities could also be in open conflict with each other . Sometimes , a particularly active alter could become the more prominent personality , which could relegate the host into a recessive role . Alternate personality states could also be modeled after an existing individual ' s personality traits . The affected individual may even dress like and use the name of the person after whom the traits were modeled . Multiple personalities also existed within the Thakwaash species , however this was a normal trait , rather than a disorder . Each personality had different beliefs , behaviors , and abilities and could be switched at will . As the Thakwaash developed , more alters would be discovered and they would improve their skill in alternating between each one . The personalities could include mentally - unstable alters , though this was not a detriment to the Thakwaash , as the problematic alters could be replaced with a more peaceable personality . This aided the Thakwaash in the insight into how others would think , which allowed for the imitation of writing and thought processes . History . Vydel Dir ' Nul , a Jedi Knight , developed the alternate personality of " Kardem " after she killed her lover , Ash B ' risko . This alternate personality was that of a Dark Jedi male and Dir ' Nul believed this person to be a separate individual . Likewise , while under the " Kardem " personality , " he " was unaware of the existence of Dir ' Nul . Graf Yonna , an operative for the Rebel Alliance , had multiple personalities as a result of the emotional trauma that he suffered when the Empire destroyed his homeworld of Bront , which killed his family in the process . His alternate personality was modeled after the traits of Parsol d ' Ahndole , an adventurer from the early days of the Old Republic , whose exploits had been dramatized in a number of holofilms . Yonna would even use d ' Ahndole ' s name . This alter was described as melodramatic , with an intense hatred toward the Empire . It also drove Yonna to perform various feats of heroism . Zuckuss , a Gand bounty hunter , also had multiple personalities , which was co - morbid with his schizophrenia . One personality adopted the devout role of a findsman and obeyed Gand language protocol to a fault . The other was a violent Corellian braggart who referred to himself in the first person and indicated that he was no longer a member of Gand society . This personality was the dominant of the two and displayed signs of insecurity . The findsman persona would surface when Zuckuss felt guilty about breaking away from Gand culture . These two personalities were in conflict with each other . It was speculated by Gawynn Karastee , the forensic psychiatrist who diagnosed Zuckuss , that the alters developed as a result of Zuckuss leaving his homeworld and may have stemmed from his role as a findsman . Blitzer Harrsk suffered from the disorder following an attack on his Star Destroyer at the Battle of Endor in 4 ABY . A piece of durasteel stabbed through his left eye and his left frontal lobe , causing two personalities to develop ; one of an irrational and megalomaniacal version of his former self , the other of his second - in - command , Bolla Thoath , who perished in the same accident . It would not be until 8 years later , having barely survived the assassination attempt at the Tsoss Beacon , that Harrsk discovered the truth . He was , however , too late to stop the Thoath persona from crashing their TIE shuttle into an asteroid to end Harrsk ' s mad campaign . Behind the scenes . Multiple personalities first appeared in sources with the June 1994 publication of West End Games ' " Cracken ' s Rebel Operatives " roleplaying supplement , most notably the entry describing the character of Graf Yonna . At this time , however , the disorder was not named , but rather described as separate personalities and delusions . Multiple personalities later appeared in February 2 , 1998 , with the publication of Aaron Allston ' s novel " " as a normal trait of the equine Thakwaash species . It was not until April 3 , 2001 when the disorder itself was again noted and explicitly named in " The Essential Guide to Alien Species " , in a journal entry attributed to Gawynn Karastee . This disorder was a retcon that was used to explain the drastic personality changes exhibited by Zuckuss in several sources , most notably between the previously - established canon from " " , and his later appearance in " The Bounty Hunter Wars " series . The mental illness then appeared in the seventeenth issue of the " Star Wars Tales " comic " Dark Journey " in October 1 , 2003 , with the appearance of Vydel Dir ' Nul . Since then , several sources , notably " The Official Star Wars Fact File 61 " and " " , have erroneously listed as being the same as the real - world diagnosis of . However , multiple personality disorder is characterized by two or more distinct personality states , experiences of possession , and discontinuities in behavior , perception , and memories . The disorder does not include any of the hallmarks of schizophrenia , which include delusional symptoms and hallucination s .