AceShowbiz - Sinead O'Connor turned to music as a substitute for therapy. The "Nothing Compares 2 U" singer was discovered dead on Wednesday, July 26 aged 56 after years of battling mental health issues, and said she spent her entire childhood being beaten up.

The admissions were made by her on a new documentary on her life and rise to fame titled "Nothing Compares", which is controversially airing on Saturday, July 29 night on Sky Documentaries days after her passing.

Sinead says in the film, directed by Belfast-born filmmaker Kathryn Ferguson, "There was no therapy when I was growing up so the reason I got into music was therapy. It was such a shock for me to become a pop star. It's not what I wanted. I just wanted to scream."

Sinead also speaks of her widely known abuse at the hands of her mum, and says her mother made her live in their garden "24/7 for a week or two." She added, "I'd be screaming, begging her to let me in. I spent my entire childhood being beaten up because of the social conditions under which my mother grew up."

The film also examines claims Sinead's former record company tried to coax her into an abortion, and examines the live US TV appearance that saw her rip up a photo of the Pope.

She adds in the documentary about her shaven-headed look, "They wanted me to grow my hair long, wear short skirts and high heels, make-up and the whole works. And write songs that wouldn't challenge anything. But I come from a country where there used to be riots in the streets over plays. That's what art is for."

Sinead shot to No. 1 with her cover of Prince's "Nothing Compares 2 U", and while filming the music video for the track couldn't stop thinking about her mum Johanna, who died in 1985 in a car crash five years before it was made.

The tear she cried during the video's making is one of the most iconic moments in music history and she said, "I didn't know I was going to cry singing it. Every time I sing the song, I think of my mother. I never stopped crying for her."