The Hairspray star has hit headlines for all the wrong reasons of late, following a string of driving incidents, months of bizarre behaviour in public, her recent arrest for drug charges and her outbursts on Twitter.com, taking aim at celebrities including Rihanna, Courtney Love and former friend Lance Bass.
However, Bell, who co-starred with Bynes on her Nickelodeon programme The Amanda Show from 1999, claims there is no cause for concern.
He tells America's Ok! magazine, "Amanda and I are close... I talk to her every day. She's a sweetheart. I had lunch with her yesterday, and she's brilliant. She's good, and she's healthy... She's in a place right now where she is searching. She's ready to be her own person, and do her own thing... She is a girl who is finding herself.
"I'm like, 'Dude, you come off crazy.' She's like, 'I know, but I don't mean to. I just changed the way I look'.
"Anytime I've ever been with Amanda, she's totally coherent, totally there, totally everything."