For seemingly no apparent reason, Amanda Bynes suddenly decided to declare Twitter war on Rihanna. The troubled former child comedienne has unleashed her fury on the younger star, even offensively claiming that Chris Brown beat Rihanna because she was ugly.

"@rihanna Chris Brown beat you because you're not pretty enough," the 27-year-old ex-Nickelodeon star wrote, adding, "@rihanna no one wants to be your lover so you call everyone and their mother that I almost named my new dog Rihanna"

It's not clear why she went into an outburst all of a sudden. She quickly deleted the distasteful Tweets, but not before the Twitterverse has screenshot them.

Rihanna has clearly read the Tweets before they got deleted because she just posted:

"Ya see what happens when they cancel Intervention?"

It's a classy response to Amanda's out-of-control and pointless digs, but classy isn't Amanda's forte these days. She posted and promptly deleted another tirade:

"@rihanna unlike ur fugly faced self I don't do drugs! U need the intervention dog! I met your ugly face in person! U aren't pretty u know it!"

To be fair, the multi-Grammy winner didn't mention Amanda's name on her Tweet. For all we know she was just referring to the recently cancelled reality TV programme "Intervention."

Amanda has been denying that she has mental issues, but insulting another person and even bringing up a past that she had no control of isn't exactly the behaviour of a sane person. Or it could be that it's all for publicity.

Her parents didn't think so. Rick and Lynn apparently think that their daughter needs professional help.

"Amanda has been clearly using drugs, yes, including marijuana, but that is just the symptom," a family insider told RadarOnline.com. "The fact is Amanda suffers from severe mental health issues that she refuses to accept. Rick and Lynn want her to seek in-patient treatment at a psychiatric hospital so she can be properly treated."

Her parents previously applied for Amanda's conservatorship, but were unsuccessful. After she was arrested for throwing a bong out the window of her New York City apartment and her subsequent trip to a hospital for psychiatric evaluation, the "retired" actress' parents allegedly consulted lawyers in hopes of getting a conservatorship.

However, they were advised that it is unlikely a judge would give them what they want. Hence, they are "absolutely powerless to do anything at this point," a source told the Web site.