Ryan Reynolds didn’t expect his father’s Parkinson’s disease to include symptoms like hallucinations and delusions.

“I just thought, ‘My dad’s losing his mind,’” the Deadpool & Wolverine star told People in a new interview to promote the actor’s partnership with Acadia Pharmaceuticals and the website More to Parkinson’s. “My father was really slipping down a rabbit hole where he was struggling to differentiate between reality and fiction.” And as a result, Reynolds said, “everyone else in his life was losing the bedrock faith and trust that they had on his point of view.”

Reynolds’ father, James Chester Reynolds, was diagnosed with Parkinson’s in 1998, when Ryan was just 22, and lived with the disease until his death in 2015, at age 74. In all that time, Reynolds recalled, his father rarely spoke about Parkinson’s and barely even said the word. “There was a ton of denial, a ton of hiding,” the actor recalled.

That might have been partly because of his father’s “pride,” which Reynolds said “was just so ingrained in him that it dictated almost everything that he did.” Reynolds continued, “My father was a man who does not share his feelings. He was a boxer, a cop, a hard-ass.” While he described James as “present” and never missing a football game, “he just didn’t have the capacity to feel, or at least share, the full spectrum of human emotion a bit.”

When his father was diagnosed with Parkinson’s, Reynolds didn’t realize that hallucinations and delusions were a common symptom; according to More to Parkinson’s, they affect 50 percent of people with the disease. Other nonmotor symptoms include anxiety and loss of mental sharpness, while motor symptoms like tremors, slow movement, and rigid muscles are better known.

Reynolds’ father began experiencing hallucinations and delusions “a few years after his diagnosis,” Terry Reynolds, Ryan’s mother, told More to Parkinson’s. “I didn’t know that they were a common part of the progress of the disease, so when I asked about it, the doctor was pretty nonchalant. I guess he just thought, well, it goes with the territory.”

For Reynolds, the delusions were the “most painful part” to watch. “There would be conspiratorial webs that he would spin about ‘this is happening’ and that ‘these people might be after me’ or ‘this person is out to get me,’” he told People. “And just stuff that was such a wild departure from the man that I grew up with and knew.”

Reynolds told More to Parkinson’s that he found his dad’s hallucinations and delusions frustrating. “They would make me almost angry because he was detached from reality,” he recalled. “But I think in retrospect what I was actually experiencing was, these symptoms that my father had were robbing me of an ability to create any kind of bridge with him in the future or any kind of closure with him before he would inevitably pass away.”

Reynolds pulled away from his father and stopped spending time with him. Upon reflection, the actor says, “I think I probably contributed to a certain degree to some of the isolation and loneliness he might have felt around this.”

Reynolds has spoken about his father’s battle with Parkinson’s in the past, including in a social media post when his dad passed away. “RIP Pops. James C. Reynolds,” he wrote in a post on Twitter (now X), before asking followers to donate and support the Michael J. Fox Foundation to support research on the disease. Reynolds has been involved with the foundation since 2008, when he ran the New York City Marathon to raise money for the org, he wrote in the Huffington Post at the time.

His father’s diagnosis “kind of galvanized everybody else [in my family], to sort of seek resources,” the actor told Today in 2014. “And for us, it’s in a strange way, it’s really kind of brought us together.”

Ten years later, as Reynolds shares a deeper look into his father’s struggle, he hopes opening up will help others enduring the same disease. “If anything is meant to come out of this chat,” he told More to Parkinson’s, “it’s that I hope people understand that there’s help available for this specific thing [hallucinations and delusions].”

Before you go, read about these celebs who have opened up about their own health issues:

This article was originally published on sheknows.com.