Billie Lourd speaks out on the cause of her mother Carrie Fisher's death

Billie Lourd has been through a traumatic 7 months. The 24-year-old daughter of the late Carrie Fisher has been dealing with the loss of her mother and her grandmother, Debbie Reynolds, and Monday's announcement about the reasons behind her mom's death.

On Monday, the Los Angeles County Coroner's Office cited sleep apnea as one of the causes of Carrie Fisher's death, but also named a mixture of drugs that were in her system at the time when she suffered a cardiac arrest while traveling on a plane late last year.

"Urine toxicology on admission to the hospital was positive for cocaine, methadone, ethanol, and opiates," the report explained.

While the variety of drugs in Fisher's system comes as a shock to the public, it seems that Lourd was already aware of the deadly drugs that were in her mother's body at the time of her death.

On Friday Lourd released a touching statement about her mother's longtime battle with drugs.

"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," Lourd said.

"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," she continued.

PHOTOS: Take a look at Billie and Carrie together

She concluded her tribute, and said, "Shame and those social stigmas are the enemies of progress to solutions and ultimately a cure. Love you Momby."

It's no doubt that Lourd is still likely reeling from her mother's passing, but she seems determined to start spreading awareness about mental health issues and drug addiction. She also seems to be leaning a lot on her friends and family, including her dad, famous Hollywood agent Bryan Lourd. Over the weekend, Billie shared a photo tribute to her dad for Father's Day:

Lourd has also been spending time with her rumored boyfriend, Taylor Lautner. They went to Stagecoach together earlier this summer and she also jetted off to Napa with friends earlier this month.

PHOTOS: A look back at the stars we've lost in 2016