Donna, says she’s afraid her 37-year-old stepdaughter, Tia, wants to kill her.

TELL DR. PHIL YOUR STORY: Have a Volatile Teen, Parent or Sibling?

“I basically have to lock myself in my home,” she says.

Donna claims that Tia is unpredictable, “has a very sick and demented mind,” and has told “lie-after-lie” about her for years.

WATCH Woman Claims Stepdaughter Has Told ‘Lie-After-Lie’ About Her For Years

Tia’s father, Jimmy, claims Tia is paranoid. He says she has accused him of physically abusing and sexually molesting her, and thinks he’s on a mission to have her committed. He denies all of it.

Jimmy also says Tia began drinking and doing drugs when she was 13.

WATCH Dad Claims His Grown Daughter Is In A ‘Loop Of Dysfunction’

In the video above, Dr. Phil says that with a history of drug abuse dating back to her teens, Tia’s thoughts and behaviors aren’t necessarily voluntary. 

"What happens is, you disrupt the neurotransmitters in the brain, and she starts getting messages that might seem very real to her,” he says.

Does Dr. Phil have a plan for Tia?

Check here to find out where you can watch Monday’s episode.

TELL DR. PHIL YOUR STORY: Know someone with outrageous behavior?

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