Sia has admitted she was "unhappy" being a pop star.
The singer/songwriter - who landed a UK top 10 with her 2000 breakthrough hit 'Taken For Granted' - was never happy with the pressures of being a recording artist and it led to a spiralling drug and alcohol addiction.
In a candid interview with Billboard magazine, Sia recalled: "All I wanted to do was write for pop stars. For one reason or another it never happened for me. Then I got seriously addicted to Vicodin and Oxycodone, and I was always a drinker but I didn't know I was an alcoholic. I was really unhappy being an artist and I was getting sicker and sicker."
The 37-year-old star - who collaborated on David Guetta's 2011 hit 'Titanium' and with Flo Rida on 'Wild Ones' - says she now prefers to rake in the cash by recording from home rather than jet around the world for concerts, as she has signed a new record contract with RCA which stipulates she doesn't have to tour or carry out promotional responsibilities.
Sia explained: "It shows the power of saying 'no'. I get to sit at home with the dogs on the sofa, record in a closet in the office, send them off and, if I'm lucky, make a million dollars."
Sia - who was treated for hyperthyroid disease - has written for the likes of Katy Perry and Rihanna, and is more focused on her songwriting than ever before.
She said: "I don't care about commercial success. I get to do what I love and communicate whatever I want."