Tori Spelling Regrets Shannen Doherty Leaving ‘90210,’ Admits Set Was Too ToxicTori Spelling Regrets Shannen Doherty Leaving ‘90210,’ Admits Set Was Too ToxicShannen Doherty, who played Brenda Walsh, left the show after Season 4 in 1994. Donny MeachamDonny Meacham