A woman who created 2500 different personalities to cope with serious abuse has found justice.

Jeni Haynes, 49 and from Sydney, was subjected to physical, sexual and emotional abuse at the hands of her father from the age of four.

Her way to survive and manage this ordeal was to create an extensive list of personalities that compartmentalised the trauma.

Psychiatrist Dr George Blair-West told News Corp that multiple personality disorder can be a tactic developed by children under the age of eight in response to abuse.

"There is nothing wrong with Jeni's human mind or any other person who suffers from dissociative identity disorder. Their mind is just coming up with an incredibly sophisticated, clever solution to a scenario that most of us could not begin to understand or relate to."

Haynes told 60 Minutes the abuse she suffered was unbearable.

"My dad inflicted, chose to inflict, severe, sadistic, violent abuse. That was completely unavoidable. Inescapable. And life-threatening. And he chose to do this every day of my entire childhood."

Her 74-year-old father, Richard Haynes, was extradited to Australia from the United Kingdom and charged with multiple counts of rape, buggery and indecent assault at the NSW District Court on February 21.

Jeni appeared at the trial and gave testimony, using her different personalities to tell her story.

"She has a memory unlike yours or my memory," Dr Blair-West said. "Her alters are living in different time-space realities, effectively. Particularly those younger ones.

"It's almost like being able to, yeah, click on a folder in a computer, open it up and read it, without any decay over a 40-year period."

After hearing her testimony, Jeni's father plead guilty to all charges within hours and, although eligible for name suppression, she decided to make a public statement so that her father's name would be known.

"I want him to walk into prison with everybody knowing what he did," she said.

Newshub.