the gifted Irish singer-songwriter who became a superstar in her mid-20s but was known as much for her private struggles and provocative actions as for her fierce and expressive music, has died at 56.

鈥淚t is with great sadness that we announce the passing of our beloved Sin茅ad. Her family and friends are devastated and have requested privacy at this very difficult time,鈥� the singer鈥檚 family said in a statement reported Wednesday by the BBC and RTE. No cause was disclosed.

She was public about her mental illness, saying that she was diagnosed with bipolar disorder. O鈥機onnor posted a Facebook video in 2017 from a New Jersey motel where she had been living, saying that she was staying alive for the sake of others and that if it were up to her, she鈥檇 be 鈥済one.鈥�

When her died by suicide in 2022, O鈥機onnor tweeted there was 鈥渘o point living without him鈥� and was soon hospitalized.

Recognizable by her shaved head and elfin features, O鈥機onnor began her career singing on the streets of Dublin and soon rose to international fame. She was a star from her 1987 debut album 鈥淭he Lion and the Cobra鈥� and became a sensation in 1990 with her cover of Prince鈥檚 ballad 鈥淣othing Compares 2 U,鈥� a seething, shattering performance that topped charts from Europe to Australia and was heightened by a promotional video featuring the gray-eyed O鈥機onnor in intense close-up.

She was a lifelong non-conformist 鈥� she would say that she shaved her head in response to record executives pressuring her to be conventionally glamorous 鈥� but her and troubled private life often overshadowed her music.

A critic of the Catholic Church well before allegations sexual abuse were widely reported, O鈥機onnor made headlines in October 1992 when she tore up a photo of Pope John Paul II while appearing live on NBC鈥檚 鈥淪aturday Night Live鈥� and denounced the church as the enemy. The next week, Joe Pesci hosted 鈥淪aturday Night Live,鈥� held up a repaired photo of the Pope and said that if he had been on the show with O鈥機onnor he 鈥渨ould have gave her such a smack.鈥�

Days later, she appeared at an all-star tribute for Bob Dylan at Madison Square Garden and was immediately booed. She was supposed to sing Dylan鈥檚 鈥淚 Believe in You,鈥� but switched to an a cappella version of Bob Marley鈥檚 鈥淲ar,鈥� which she had sung on 鈥淪aturday Night Live.鈥�

Although consoled and encouraged on stage by her friend Kris Kristofferson, she left and broke down, and her performance was kept off the concert CD. (Years later, Kristofferson recorded 鈥淪ister Sinead,鈥� for which he wrote 鈥淎nd maybe she鈥檚 crazy and maybe she ain鈥檛/But so was Picasso and so were the saints.鈥�)

She also feuded with Frank Sinatra over her refusal to allow the playing of 鈥淭he Star-Spangled Banner鈥� at one of her shows and accused Prince of physically threatening her. In 1989 she declared her support for the Irish Republican Army, a statement she retracted a year later. Around the same time, she skipped the Grammy ceremony, saying it was too commercialized.

In 1999, O鈥機onnor caused uproar in Ireland when she became a priestess of the breakaway Latin Tridentine Church 鈥� a position that was not recognized by the mainstream Catholic Church. For many years, she called for a full investigation into the extent of the church鈥檚 role in concealing child abuse by clergy. In 2010, when Pope Benedict XVI apologized to Ireland to atone for decades of abuse, O鈥機onnor condemned the apology for not going far enough and called for Catholics to boycott Mass until there was a full investigation into the Vatican鈥檚 role, which by 2018 was making international headlines.

鈥淧eople assumed I didn鈥檛 believe in God. That鈥檚 not the case at all. I鈥檓 Catholic by birth and culture and would be the first at the church door if the Vatican offered sincere reconciliation,鈥� she wrote in the Washington Post in 2010.

O鈥機onnor announced in 2018 that she had and would be adopting the name Shuhada鈥� Davitt, later Shuhada Sadaqat 鈥� although she continued to use Sin茅ad O鈥機onnor professionally.

鈥淗er music was loved around the world and her talent was unmatched and beyond compare,鈥� Irish Prime Minister Leo Varadkar said in a statement on social media.

O鈥機onnor was born on Dec. 8, 1966. She had a difficult childhood, with a mother whom she alleged was abusive and encouraged her to shoplift. As a teenager she spent time in a church-sponsored institution for girls, where she said she washed priests鈥� clothes for no wages. But a nun gave O鈥機onnor her first guitar, and soon she sang and performed on the streets of Dublin, her influences ranging from Dylan to Siouxsie and the Banshees.

Her performance with a local band caught the eye of a small record label, and, in 1987, O鈥機onnor released 鈥淭he Lion and the Cobra,鈥� which sold hundreds of thousands of copies and featured the hit 鈥淢andinka,鈥� driven by a hard rock guitar riff and O鈥機onnor鈥檚 piercing vocals. O鈥機onnor, 20 years old and pregnant while making 鈥淟ion and the Cobra,鈥� co-produced the album.

鈥淚 suppose I鈥檝e got to say that music saved me,鈥� she said in an interview with the Independent newspaper in 2013. 鈥淚 didn鈥檛 have any other abilities, and there was no learning support for girls like me, not in Ireland at that time. It was either jail or music. I got lucky.鈥�

鈥淣othing Compares 2 U鈥� received three Grammy nominations and was the featured track off her acclaimed album 鈥淚 Do Not Want What I Haven鈥檛 Got,鈥� which helped lead Rolling Stone to name her Artist of the Year in 1991.

鈥淪he proved that a recording artist could refuse to compromise and still connect with millions of listeners hungry for music of substance,鈥� the magazine declared.

O鈥機onnor鈥檚 other musical credits included the albums 鈥淯niversal Mother鈥� and 鈥淔aith and Courage,鈥� a cover of Cole Porter鈥檚 鈥淵ou Do Something to Me鈥� from the AIDS fundraising album 鈥淩ed Hot + Blue鈥� and backing vocals on Peter Gabriel鈥檚 鈥淏lood of Eden.鈥� She received eight Grammy nominations overall and in 1991 won for best alternative musical performance.

O鈥機onnor announced she was retiring from music in 2003, but she continued to record new material. Her most recent album was 鈥� released in 2014 and she sang the theme song

The singer married four times; her union to drug counsellor Barry Herridge, in 2011, lasted just 16 days. O鈥機onnor had four children: Jake, with her first husband John Reynolds; Roisin, with John Waters; Shane, with Donal Lunny; and Yeshua Bonadio, with Frank Bonadio.

In 2014, she said she was joining the and called for its leaders to step aside so that a younger generation of activists could take over. She later withdrew her application.

This story includes discussion of suicide. If you feel like you are in crisis or are considering suicide, please call the Crisis Centre BC suicide hotline at 1-800-784-2433.

Other resources include: Canada Suicide Prevention Service at Toll free: 1-833-456-4566. You can also text 45645 or visit the online chat service at .