Sia opened up about her bipolar disorder diagnosis in a candid interview on Howard Stern's radio show. The 38-year-old Australian hitmaker told Stern that she believes her condition was a result of smoking marijuana as young as 13.

According to, when asked about her disorder, she responded, “What I do think, is that I smoked too much pot as a kid,” she said.

“My brain wasn't fully formed," she admitted before adding, "I f***ed my brain up."

Sia suffers from stage phobia and rarely performs in front of crowds without covering her face. She has recently spoken out about her battles with depression, anxiety and alcoholism as well.

While speaking with The New York Times in April, Sia revealed that after her bipolar diagnosis, she took alcohol, antidepressants and painkillers, including Xanax and OxyContin, and became addicted to the substances just to get through live shows.

“I was in the back lounge, high on Xanax and alcohol, watching every episode of ‘E.R.’ from the beginning," she told the paper. "When you're in a different place every day, there’s this kind of madness that sets in. It’s easy to get away with getting high, because everybody’s drinking on the road. None of my friends thought I was an alcoholic, and neither did I.”

After a near suicide attempt in 2010, she enrolled in a 12-step program with the help of a friend.

Now, Sia is one of music's most in-demand songwriters. She contributed the vocals to David Guetta's 'Titanium' and Flo Rida's 'Wild Ones,' and has also written a lot of hits by some of music's biggest tastemakers, including Rihanna's 'Diamonds,' Ne-Yo's 'Let Me Love You' and Britney Spears' 'Perfume.'