Billie Lourd, whose celebrity mother passed away a few months ago, says the only thing Mrs. Fisher would want is to make people speak openly about their struggling, in part battling with addictions. ‘My mom battled drug addiction and mental illness her entire life. She ultimately died of it,’ actress Billie Lourd stated, adding that her mom did a great social work to overcome the stigmas around the addictions and mental health disorders. The author and Star Wars icon’s primary cause of death was sleep apnea but an autopsy report released this week concludes that Fisher was a drug addict and it was a key factor. Fisher had a long history of drug use which she chronicled in such books as Postcards From the Edge and Wishful Drinking. She also had bipolar disorder which she also wrote about and spoke publicly about extensively.