Lance Bass is ''scared'' for Amanda Bynes.

The former NSync singer has been friends with the troubled former actress since he produced her movie 'Love Wrecked' in 2005 and Lance admitted he is worried by her recent bizarre antics.

Speaking on Las Vegas radio's Mark and Mercedes show, he said: ''No one is able to get to her. I'm actually really scared for her, and I hope someone is able to get to her to give her the help she needs.

''It's one of those situations where obviously there's some mental problems there and she's not able to see that. We all are [able to see it].''

However, Amanda, who was charged with attempted evidence tampering, reckless endangerment and marijuana possession in court last week, after being arrested at her New York City apartment, hit back at Lance on Twitter.

She wrote: ''I ignored Lance Bass on twitter and now he is saying I have a mental illness. Sorry you're an ugly ex boy band member w/ no talent or career (sic).''