Patricia Arquette on Her Dad’s Alcoholism, Relating to Maggie Murdaugh (Exclusive)

Patricia Arquette’s latest role hit close to home.

The actress plays Maggie Murdaugh in Hulu’s new limited series, Murdaugh: Death in the Family, which is based on the shockingly true story of a South Carolina family and its patriarch, Alex Murdaugh, who was convicted of killing his wife Maggie and their son Paul.

During Alex’s trial, he admitted to having a lifelong addiction to opioids — his lawyer claimed his client spent $50,000 a week on drugs — and his son, Buster, said that the family was aware of Alex’s addiction as well. Another claim made by Alex during the trial was that he took more than 2,000 milligrams of painkillers a day in the months leading up to Maggie and Paul’s 2021 deaths.

To play Maggie, who was married to Alex for years before her death, Arquette tells PEOPLE how her own childhood experiences witnessing the devastating effects of addiction informed her portrayal.

“I grew up in a family where there were substance abuse issues with my dad and alcoholism and betrayals,” she says. “And my dad was charming, and I loved my dad.”

Given her father’s struggles — she’s the youngest daughter of actor Lewis Arquette and Brenda Denaut, who shared five kids — Patricia says she “definitely got modeled” behavior that parallels that of the Murdaugh patriarch, who was secretive about his demons throughout his life.

Patricia, 57, also “saw how hard [her dad’s addiction] was for my mom” to deal with, which also informed how she interpreted Maggie’s story.

As she prepared to take on the role — alongside Jason Clarke as Alex — Patricia says she “looked at alcoholism” and how it influences everyone around it.

“There’s kind of normal patterns in a dysfunctional family, even just with alcoholism or addiction,” she says.

In the case of the Murdaugh family, both Alex and his wife were doing things they were not supposed to be doing in order to facilitate Alex’s recovery. “There’s a reason they say these things are a family disease, because everything gets distorted. And when you have lies and pathological manipulation and all of this kind of stuff — and betrayal — it’s just layer after layer of things that are hidden, and he’s hiding so many things.”

Patricia adds of how she understands Maggie, “I really wanted to honor her as a mother of this family, who’d been with [Alex] since college and got very normalized to his crazy behavior … and his family’s access and capacity and privilege to be able to get away with everything, and how that could steamroll and steamroll.”

“They were dealing with so many different things — addictions and alcohol and drugs and all of these different things, betrayals,” she says of the family.

“What was really interesting to me about this story was this charming, charismatic personality who is the head of the family, but also a pathological liar, betrayer, manipulator. And for this woman, for her to start realizing, ‘I have no clue who I’m married to’ — where does it end? All of these layers of layers of deception and gaslighting and manipulation and who are you?”

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New episodes of Murdaugh: Death in the Family drop Wednesdays on Hulu.