Margot Kidder
© Gilbert Carrasquillo/FilmMagic
Margot Kidder's death has been ruled a suicide. Park County, Montana Coroner Richard Wood confirmed to the Associated Press that Kidder died "as a result of a self-inflicted drug and alcohol overdose." The actress was found by a friend in her Livingston, Montana, home on May 13. She was 69.

Kidder's daughter, Maggie McGuane, told the AP, "It's a big relief that the truth is out there." McGuane, an only child, noted that Montana has one of the highest suicide rates, adding, "It's important to be open and honest so there's not a cloud of shame in dealing with this."

McGuane continued, "It's a very unique sort of grief and pain. Knowing how many families in this state go through this, I wish that I could reach out to each one of them."

Kidder is best remembered for playing Lois Lane opposite Christopher Reeve in the Superman films. The Canadian-born actress had long been open about drug and alcohol addictions, which she said partially triggered her very public breakdown in 1996. The screen icon was equally open about her bipolar diagnosis.

When speaking about her lifelong struggle with mental illness, she told the Los Angeles Times, "I knew I was different, had these mind flights that other people didn't seem to have. And I had deep depressions." Kidder became one of Hollywood's first and most prominent mental health advocates.

Hollywood has been rocked by suicides this year, with Kate Spade and Anthony Bourdain also taking their own lives.