Sleep apnea contributed to her death, according to a coroner report, but the official cause of death is undetermined.

Nearly six months after she passed away, Carrie Fisher’s cause of death has been revealed. Officials said in a statement yesterday that, though sleep apnea and other factors contributed, “the manner of death has been ruled undetermined.” Fisher had a heart attack on December 23 while en route from London to Los Angeles, ultimately dying on December 27; her mother, Debbie Reynolds, had a stroke and died the next day.

“Drug use” was also listed in the coroner’s report, which Fisher’s daughter, Billie Lourd, addressed in a statement released to People: “My mom battled drug addiction and mental illness her entire life,” she wrote. “She ultimately died of it. She was purposefully open in all of her work about the social stigmas surrounding these diseases.

“She talked about the shame that torments people and their families confronted by these diseases. I know my Mom, she’d want her death to encourage people to be open about their struggles. Seek help, fight for government funding for mental health programs. Shame and those social stigmas are the enemies of progress to solutions and ultimately a cure. Love you Momby.”

The “Star Wars” actress was open about her substance abuse throughout her life, including in her autobiographical one-woman play and subsequent book “Wishful Drinking.” She was 60 at the time of her passing.