A.J. McLean has checked himself into rehab.

The Backstreet Boys singer - who has previously been treated for depression, anxiety and excessive consumption of alcohol - voluntarily checked himself into a treatment Clinic on Monday (10.01.11) after realising he needed help, but insisted it would not affect the group.

In a statement he said: "For personal reasons, I've checked myself into a rehab clinic. With 2011 being a busy year for Backstreet, I want to be healthy and perform and sing for people at my very best and happiest.

"None of this will affect our current tour plans and I look forward to seeing everyone really soon! Thank you for all of your support and respecting my family and friends privacy during this time."

A.J. - real name Alexander James - has previously dropped hints he was struggling with alcohol issues, writing on his twitter account @skulleerozon on Sunday (09.01.11): "Thank u all for my bday wishes and tweets:)! Its gonna be a great year! I love u all and wish me luck! I start my sober Journey tomm! Ttfn! (sic)"

He added in a post on Monday: "Hey all wish me luck! This is gonna be an amazing year for me and all around me! I love u all and appreciate all the love and support.

"See u on The Other Side!(sic)"

A.J's bandmates - Brian Littrell, Nick Carter and Howie Dorough - tweeted their support for him, saying: "we love and support our brother @skulleeroz. We are proud of him and thank all of our fans for the support. We love u!"

A.J. has been engaged to Rochelle Deanna Karidis since last year, with their wedding set to take place on May 14.

Backstreet Boys are currently planning a summer 2011 tour with New Kids On The Block.