Hayden Panettiere Costar Justin Chatwin Says She Was Struggling, Lonely on Final Movie

Hayden Panettiere was "struggling" and "really lonely" on what turned out to be the final movie she ever filmed ... so says her "Sleepwalker" costar, Justin Chatwin.

Justin opened up about their connection while speaking to People ... saying they grew close while filming in 2025 because she was so real with him. He explained, "[Actors are] trained to be on, and I really liked spending time with her because she took that off, and she was authentic with me about her life and she opened up about her struggles with addiction."

The Canadian actor originally met Hayden while she was starring on "Heroes" in the mid-2000s, and then reconnected for "Sleepwalker," a psychological thriller about domestic abuse -- something Hayden had been through.

Justin told People he "could tell she was struggling," adding ... "I was like, 'I don't think it's this movie' ... There's a handful of women that I've worked with that I really liked, and I really loved working with her, but I also know that she was really lonely."

He further reflected, "Hayden seemed different when I met her this time than when I met her in the early years ... I've been sober for 15 years, so I know this world of addiction, and Hollywood -- it takes, and it takes from youth."

As you know, Hayden never hid her mental health and substance abuse issues -- even giving up custody of her daughter she shares with Wladimir Klitschko to focus on her health. It was also no secret she had been involved in a few domestic violence incidents with her on-again, off-again boyfriend Brian Hickerson.

TMZ learned Hayden and Brian were back together, but were hiding their relationship at the time of her death.

As we reported, Hayden was found unresponsive in a South Carolina apartment Sunday and pronounced dead after medics attempted to revive her. Dispatch audio mentioned a possible overdose, and the preliminary autopsy results say there were no signs of trauma.