Sinead O'Connor pulls out of tour, blames bipolar disorder

Just one month after announcing a North American trek, Sinead O'Connor has canceled the outing, citing issues with bipolar disorder.

The Irish singer/songwriter posted a message yesterday (4/23) at her Facebook page, explaining that she is "unwell."

"As you all know I had a very serious breakdown between December and March and I had been advised by my doctor not to go on tour but didn't want to 'fail' or let anyone down as the tour was already booked to coincide with album release," the post states. "So very stupidly I ignored his advice to my great detriment, attempting to be stronger than I actually am."

The canceled 11-date spring and summer excursion was scheduled to begin May 12 in Milwaukee and run through a July 28 appearance at Calgary Folk Music Festival in Alberta.

In February, O'Connor unveiled her ninth studio effort, "How About I Be Me (And You Be You)?," on the London indie label One Little Indian. The album, which marks O'Connor's first since 2007's "Theology," peaked at No. 20 on Billboard's Alternative Albums chart.

In 2007, O'Connor discussed her bipolar diagnosis on "The Oprah Winfrey Show."

"Everything just became too much, and the best way I can describe it to you is you're so sad, just terribly sad, that you're like a bucket of water with holes in it," the Grammy winner said in the interview. "Every pore of you is crying and you don't even understand why or what."

O'Connor is well-known for her 1990 album, "I Do Not Want What I Haven't Got," which features the hit single "Nothing Compares to U." The collection, which earned a 1991 Grammy nomination for Best Alternative Music Performance, topped The Billboard 200, as well as charts in the U.K., Switzerland, Austria and Canada.