Sinead O'Connor has cancelled the remainder of her 2012 tour.

The "Wolf is Getting Married" hitmaker - who has suffered a series of public breakdowns and relationship issues with husband Barry Herridge in recent months - has claimed it is with "regret" she is ending the tour but is doing so because of "bipolar disorder."

"With enormous regret I must announce that I have to cancel all touring for the year as am very unwell due to bi polar disorder. 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. So very stupidly I ignored his advice to my great detriment, attempting to be stronger than I actually am. I apologize sincerely for any difficulties this may cause. While touring will be cancelled I do hope and plan to appear at the Curtis Mayfield tribute in The Lincoln Centre in July.(sic)" she wrote on her website.

Sinead checked into a hospital for depression in January, claiming she was regularly "misdiagnosed" with bipolar disorder.