Bass and Bynes
FilmMagic; Splash News Online
05/30/2013 AT 02:00 PM EDT
's odd public behavior
– and recent arrest
– is worrying one of her old friends.
While calling into Las Vegas radio's Mark and Mercedes show on Wednesday, Lance Bass
spoke of Bynes, saying, "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]." (The actress's attorney, who's representing her in a DUI case in Los Angeles, says there's nothing to worry about, though, telling PEOPLE recently, "I think Amanda's fine. I have no problems with her whatsoever. She's a fine client.")
Bass produced Love Wrecked
in 2005, in which Bynes starred. The movie led to their friendship.
And while Bass didn't indicate how long it's been since the two have spoken, time hasn't stopped him from worrying about the troubled starlet.
"No one is able to get to her," he told the radio station. "I'm actually really scared for her, and I hope someone is able to get to her to give her the help she needs."
Bynes later replied on Twitter
: "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. I haven't spoken to Lance Bass in 11 years. To say I have a mental illness out of nowhere makes me lash out! You're making me crazy!"