Amanda Bynes -- Friends Waiting for Something Really Bad To Happen

Amanda Bynes can't get the help she needs until something really bad happens ... because her parents will not re-establish a conservatorship ... TMZ has learned.

Multiple sources connected with the family tell TMZ ... Amanda's parents do NOT think she has a mental illness. As one source put it, "They think she's a bratty kid who thumbs her nose at them and smokes a lot of pot."

We're told everyone around her parents are urging them to get the conservatorship, but so far no luck. That said, it's impossible to put Amanda on a 5150 psychiatric hold until she creates a substantial risk to herself or others.

We're also told various professionals are trigger ready to get the 5150 if Amanda goes off the rails, and they believe it's only a matter of time.