Kevin Federline’s Bombshell Memoir Reportedly Sent Britney Spears ‘Over the Edge’ Before Arrest

Britney Spears has been having a tough time, and ex-husband Kevin Federline’s explosive memoir may have been the catalyst.

After the “Circus” singer, 44, was arrested for allegedly driving under the influence on Wednesday, March 4, and processed at the Ventura County Sheriff’s Office, a source told Page Six that her behavior “has become increasingly erratic in recent months.”

The source claimed that Federline’s memoir, You Thought You Knew — which was released in October 2025 and included many bombshell claims about his ex-wife — “really sent her over the edge” and impacted Spears “emotionally.”

“She goes from being fine to being not,” the source said, claiming that it’s been “downhill” ever since Federline released the book.

As Globe previously reported, the former backup dancer, 47 — who shares sons Sean Preston, 20, and Jayden James, 19, with Spears — alluded during the press tour for the memoir that his ex was dealing with substance abuse.

During an interview on Piers Morgan Uncensored, Piers Morgan brought up how Federline wrote in his book that Spears was “doing cocaine while she was still nursing your boys” and asked him if the Grammy winner was on “that kind of substance.”

“It is that, all of it,” Federline replied. “So much more.”

Following Spears’ recent arrest, TMZ reported that an unknown substance was found in her car, according to sources familiar with the investigation. The outlet reported that the substance is now being tested and it will be part of the arrest.

Spears was reportedly released from jail around 6 a.m. on Thursday. The mother of two was transported to the hospital early Thursday morning to have her blood drawn after being pulled over, TMZ also reported.

Page Six’s source said that Spears “feels like she gave Kevin everything that he wanted over the years” and “paid him so much money,” but he still “exploited her” with his memoir.

“He used her; he wanted to ruin her,” the insider added. “And that was a really hard pill to swallow; it absolutely killed her that someone would want to damage her so much.”

Amid Federline’s claims last year when his book was being promoted, a rep for the singer told People, “With news from Kevin’s book breaking, once again he and others are profiting off her and sadly it comes after child support has ended with Kevin.”

“All she cares about are her kids, Sean Preston and Jayden James and their well-being during this sensationalism,” the statement added. “She detailed her journey in her memoir [The Woman in Me].”