Founding member of Dream Theater Mike Portnoy has quit the group after his bandmates refused to take a hiatus so he could enjoy a much-needed break.

The drummer helped form the band in 1985 but decided he was burning out under the constant pressure of work.

Portnoy asked the four other members if they could take some time out in the hope he could return to making music with them when he recovers.

But he claims he was forced to walk away completely when they made it clear they would be continuing without him.

In a statement announcing the news, the band says, "It is with profound sadness - regret - we announce that Mike Portnoy, our lifelong drummer and friend, has decided to leave Dream Theater. Mike's stature in the band has meant the world to all of us professionally, musically and personally over the years. There is no dispute: Mike has been a major force within this band... All of us in Dream Theater wholeheartedly wish Mike the best on his musical journey."

But Portnoy released his own statement revealing his "hurt" over their decision to continue without him: "I really needed a break from the band in order to save my relationship with the other members and keep my DT spirit hungry and inspired.

"Sadly, in discussing this with the guys, they determined they do not share my feelings and have decided to continue without me rather than take a breather... I even offered to do some occasional work throughout 2011 against my initial wishes, but it was not to be... While it truly hurts for me to even think of a Dream Theater without Mike Portnoy (hell, my father named the band!), I do not want to stand in their way, so I have decided to sacrifice myself and simply leave the band so as to not hold them back against their wishes."

Earlier this year, Portnoy stepped in to temporarily replace Jimmy Sullivan in Avenged Sevenfold after the drummer's death from an accidental overdose of prescription drugs in December.