Psychology Case Study: Dissociative Identity Disorder Case of Billy Milligan

Lesson Transcript
Instructor: Elisha Madison

Elisha has Master's degree in Ancient Celtic History & Mythology, as well as a Bachelor's in Marketing. She has extensive experience creating & teaching curricula in college level education, history, English, business and marketing.

Billy Milligan commited several crimes but was found innocent due to his dissociative identity disorder (DID), which causes individuals to develop more than one personality. Dive deep into Milligan's case study, his DID, personalities, and crimes. Updated: 04/04/2022

This lesson addresses the topic of suicide. If you or someone you know is struggling with thoughts of suicide, please reach out for help. The following website can provide support:

Dissociative Identity Disorder

Dissociative Identity Disorder (DID) is the disorder when someone has a ''disruption of identity.'' Originally called Multiple Personality Disorder (MPD), this disorder means an individual has two or more personalities, with one active while the others lie dormant. This results in chunks of time being lost for the main personality. The additional personalities can be any age or gender and tend to have unique behaviors, speech patterns, and actions.

Most psychologists agree that DID usually results from a traumatic experience or experiences. Individuals use their alter personalities to escape from the emotional or physical abuse of this trauma.

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  • 0:04 Dissociative Identity Disorder
  • 0:45 The Case of Billy Milligan
  • 1:46 Billy Milligan's Personalities
  • 3:26 Billy Milligan's Crimes
  • 5:02 Lesson Summary
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The Case of Billy Milligan

Billy Milligan is one of the most famous cases of DID. He was the first person in the United States with this disorder who was found not guilty of his crimes by reason of insanity. During the trial, many psychologists argued about the existence of DID and assumed it was a ploy rather than a valid disorder. Since Billy Milligan's was found not guilty by reason of insanity, it gave credence to the disorder.

Billy Milligan was born on Valentine's Day, 1955. His father, John Morrison, had an affair with his mother, which resulted in two children. Morrison was a comedian who suffered from depression and committed suicide when Milligan was only four. This may have been the start of Billy's disorder, but it's unknown. Eventually, Billy's mother married Chalmers Milligan when Billy was eight years old. Billy later accused his stepfather of raping him, burying him alive, and hanging him by his fingers and toes. However, this was never proven, although it could be a definite reason for Billy's dissociative identity disorder.

Billy Milligan's Personalities

During his lifetime it was determined that Billy had 24 separate personalities. He gained new ones during his treatment, because of the environment of the health facilities and the assessment of the doctors. Each of the personalities had their time in the ''spotlight'' as Billy called it. There were two subsections of personalities. The first ones were protective and usually good people. The second ones were the ''undesirables,'' which often got Billy into trouble, so Billy did not like to mention them. The personalities from the first group were a few that were seen the most.

First there was Ragen, a 23-year-old Yugoslavian, and he was the strongest in physical ability of all the personalities, also called ''the keeper of the hate.'' Ragan spoke with an accent and was there to protect Billy and the weaker personalities from the harsher world outside. He also is the personality that committed the robberies.

There was Adalana, which was one of the very few female personalities. She was 19 and a lesbian who desired love, and was willing to use violence to obtain it. She also is the main reason for the court cases, being the active personality during the rapes. She's also one of the few personalities who could take control without permission.

There was Arthur, who was an intelligent 22-year-old with an English accent. He was very strategic and could choose when to be the active personality.

There was Allen, who was the only smoker in the group. He was often the one to help Billy get out of trouble. He assumed control when Billy needed to talk his way out of a bad situation. He was also right-handed, when Billy was actually left-handed.

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