AceShowbiz -

Nearly six months after the passing of Carrie Fisher, the cause of her death has finally been revealed following the release of her autopsy results. The Los Angeles County Department of Medical Examiner - Coroner confirmed that Fisher passed away from sleep apnea and "other undetermined factors."

Fisher went into cardiac arrest while on a plane traveling from London to Los Angeles late last year. The "Star Wars" actress was immediately transported to a nearby hospital, where she was pronounced dead five days later.

According to Associated Press, the coroner has ruled atherosclerotic heart disease and sleep apnea to have contributed to Fisher's passing. An exact cause could not be pinpointed, but it was found that there was a buildup of fatty tissue in the walls of her arteries. The news outlet went on to add that her cardiac arrest was caused by multiple drug intake along with "significance not ascertained."

Shortly after the Medical Examiner's ruling was made public, Fisher's daughter Billie Lourd released a statement. "My mom battled drug addiction and mental illness her entire life. She ultimately died of it. She was purposefully open in all of her work about the social stigmas surrounding these diseases," she shared in the statement obtained by PEOPLE.

"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," the 24-year-old added, "Love you Mommy."