By Jen Heger - Breaking Celebrity News Assistant Managing Editor

On the day that Justin Timberlake married Jessica Biel, an attorney told a jury in a Los Angeles courtroom that Britney Spears "changed" and "became depressed' after her break-up with the former NYSNC singer in 2003, Breaking Celebrity News is reporting.

Jamie Spears' attorney, Leon Gladstone, told jurors in his opening statement Friday that Brit and Justin "had a big relationship, and it ended painfully. In 2003 her parents noticed that she had changed over the breakup of her and Justin and noticed she was depressed….Britney went to Vegas and got married to a childhood friend for 55 hours and they realized that she was becoming distant with her parents and become concerned she was using illegal substances."

As Breaking Celebrity News previously reported, Britney's "former manager," Sam Lutfi is suing Britney and her parents, Lynne and Jamie Spears for breach of contract, libel and defamation for comments Lynne made in a book about her life. The trial is expected to last nearly three weeks, with Lutfi, Lynne, Jamie and Brit's fiance, Jason Trawick, all scheduled to testify.

In 2006 everything changed once again for Britney, after Kevin Federline filed for divorce, amid drug abuse allegations, according to Gladstone: "Jamie does an intervention at Britney's house and she agrees to go to rehab in Antigua, but never checks in...Britney did check into rehab eventually, and checked out after one day."

Spears finally went to Promises for 30 days, but