Brody Jenner thinks his former best friend Spencer Pratt has gone off the deep end.
"I actually think he's kind of lost it a little bit," Jenner, 26, said on the Kidd Kraddick in the Morning radio show Wednesday.
The new issue of Us Weekly reports Pratt, 26, has major rage issues. On the May 11 episode of The Hills, he had a violent outburst after Heidi's sister Holly confronted him about a crude remark he made about their mother being "just a vagina."
Said Jenner, "Lately, it hard for me -- even as someone who used to be best friends with him -- to see what's real and what's not as far as he goes... I see he wants attention."
PHOTOS: Spencer and Heidi's drama-filled wedding
Jenner also said Pratt "got all crazy with those crystals," on which Us Weekly has reported the Pratts have spent $400,000.
Us Weekly also reports that the couple are in "panic mode" about losing their source of income because neither has taped since Mid-April. (Spencer was suspended from the MTV hit after threatening to kill a producer; Heidi's role was reduced after she objected to a faux-divorce story line.)
A source tells Us Weekly show creator Adam DiVello "said he doesn't think Heidi and Spencer will come back for the series finale."
VIDEO: Spencer makes Holly's sister cry
For more - including how Heidi hasn't spoken to her mom since the premiere; how Spencer has "preyed" on Heidi's insecurities and ruined her self-esteem; how pals fear Spencer could "snap at any minute" and how their sad, desperate hunger for fame has left them friendless ("No one ever visits," says a source) - pick up the new Us Weekly today!