Malcolm Young left AC/DC because of dementia

A dementia diagnosis forced Malcolm Young to quit AC/DC.

The guitarist's family confirmed today that "Malcolm is suffering from dementia" in a statement to Billboard. They thanked fans for "respecting their privacy."

In April, Young announced that he'd be taking a break from AC/DC. Last week, a post on the band's website said his departure was permanent: "Unfortunately, due to the nature of Malcolm's condition, he will not be returning to the band."

The Australian rockers will release new album Rock or Bust on Dec. 2, the first album in the band's 41-year history without Young.

"Malcolm Young has been a critical element of the AC/DC guitar sound for decades," Guitar Player editor in chief Michael Molenda told USA TODAY last week. "His edgy tone and punch-in-the-face grooves pretty much define what hard-rock guitarists should aspire to.

"But the Young family has always been resilient."

Young co-founded the band in 1973 with his brother, Angus Young.

Contributing: Patrick Ryan