Mark O’Connell, the longtime drummer of Long Island-based emo ensemble Taking Back Sunday, has announced his departure from the group after almost 25 years of membership.

O’Connell detailed his exit from the group in a lengthy post shared on social media, telling his followers that “after nearly 25 years as the drummer of Taking Back Sunday, I want to confirm that I am no longer with the band”.

Via his account (which still reads @markoconnelltbs), O’Connell reflected on his time within the band and thanked fans for being the “heartbeat” of Taking Back Sunday and “a huge part” of his life for almost a quarter of a century. “I owe it all to you,” he wrote.

“My departure wasn’t an easy decision, and it wasn’t entirely my own,” he continued. “Over the past few years, l’ve focused on my family and personal growth, including committing to my sobriety. Unfortunately, during this time, I didn’t always feel the support I needed from those I thought of as brothers, and creative differences made it hard to move forward together.”

News of O’Connell’s departure also coincides with the release of his first piece of solo music, with his “Brain Dead” single being released on Dec. 31. Per his statement, O’Connell will be releasing more music in the near future.

“I’m excited to share that I’ll be releasing new music soon-both as a solo artist and with some old friends,” he explained. I’ve poured my heart into this project, and I can’t wait to share it with you. This is a new chapter for me-one of passion, creativity, and hope. I hope you’ll join me on this journey as we continue to be a part of each other’s stories.

“That said, I’m grateful for the incredible memories with each of my bandmates-and all of you, as well as all the opportunities along the way,” he continued. “I’m choosing to focus on the good as l move into this next chapter.

“Thank you again for everything. I’m proud of what we built together, and I’m even more excited about what lies ahead.”

Taking Back Sunday formed in 1999, but experienced a number of lineup changes in its initial years, including the departure of future Brand New frontman Jesse Lacy in 2000. The following year, founding drummer Steven DeJoseph would leave due personal issues preventing widespread touring, with O’Connell taking his place. That same year would also see founding vocalist Antonio Longo replaced by Adam Lazzara.

In 2018, founding guitarist Eddie Reyes announced he would be leaving the band, with a statement from the group citing “personal reasons” for his exit. Currently, only guitarist John Nolan (who left in 2003 to form Straylight Run before his 2010 return) remains from the band’s original lineup.