Amanda Bynes -- I'd Like To Slit Dad's Wrists ... And Throw Him in a Ditch (AUDIO)

Amanda Bynes dreams of murdering her dad, slitting her mom's wrists and burning her house down, and she attacks a friend, telling him, "You're so gay it hurts my feelings" ... and it's all on tape.

The audio was recorded a week ago by one of Amanda's West Hollywood roommates as they drove. It's the first time we've been able to hear Amanda's ramblings when she goes off the rails.

The first audio is tirade against her parents, wishing them dead. The second audio is a rant that ends with a homophobic attack.

Members of Amanda's family tell TMZ ... they wanted us to post the audio ... which could be a wake-up call for medical professionals to intervene and get her help.