Leif Garrett's been battling substance abuse problems for years, which is why he took part in Season 4 of 'Celebrity Rehab.' However, he stormed out of the Pasadena Recovey Center, later telling 'The Los Angeles' Times that producers encouraged him to relapse for dramatic purposes.

Last night Bob Forrest and Rachel Uchitel checked up on Garrett as part of 'Celebrity Rehab Revisited' (Sun., 9PM ET on VH1) and things did not go too well. Garret told the pair that he'd been taking lots of painkillers following a serious motorcycle accident, and then he admitted dabbling in marijuana and booze.

That's when Bob criticized Garrett's "cavalier and laissez-faire attitude toward alcohol," which did not sit well with the former teen idol. Saying "I really do not appreciate it," Garrett walked out. Again.

It's the third episode of 'Celebrity Rehab' (Wed., 10PM ET on VH1), and Leif Garrett wants out. "I need peace in my life. I'm tired of the [beep] banter ... I'm tired of you guys fighting." To his fellow rehabbers who think he's bluffing, he threatens, "Watch me."

Later that night, Jason Davis and Rachel Uchitel try talking him out of leaving the program. "If you leave, I personally will be upset," says Uchitel. But he dramatically stomps out of the Pasadena Recovery Center.

Maybe it's all that pressure to be super-cute and squeaky-clean, but it seems like when child stars go bad, they go really, really bad. Whether it's drugs, porn or whatever it is Gary Coleman does, we combed TV history to compile a list of child stars who have fallen the farthest.

Can we all agree that if you're a TV, film, or music star and you are reduced to going on a show called Celebirty Bull Riding, your career has pretty much at its lowest point?

It's Ty Murray's Celebrity Bull Riding Challenge, to be precise, and it premieres tonight at 9 on CMT. The celebs (or "celebs") involved in the six episode show include Leif Garrett, Stephen Baldwin, Vanilla Ice, and Johnny Fairplay from Survivor (the one who lied about his grandmother dying). The object of the show is for the gentlemen to learn how to rides bulls so they can participate in a rodeo in Nashville.

Lifting its name from a Green Day song, the E! network is launching a series called Boulevard of Broken Dreams. Much like its True Hollywood Story, this series is about the rise and fall of Hollywood stars. Many of the subjects chosen for the series are dead, while others have just plain screwed up their lives after becoming famous.

Here's a list of the stars to be featured. Which one of these things is not like the others?

• Chris Penn, deceased brother of Sean Penn;
• Krissy Taylor, deceased sister of model Niki Taylor;
• Mitch Hedberg, deceased comedian;
• Leif Garrett, former teen idol and current joke;
• Lauryn Hill, singer who... WTF?