A mistress, a twin and an aging diva - and that’s just the beginning of Celebrity Rehab, season 4. A whole new cast of has-beens, never-weres and true former icons will come together, under the guidance of Dr. Drew Pinsky, to learn how to kick their addictions. Now find out how Donald Trump, Tiger Woods and half a million dollars are involved with the show’s production.

Twin Jeremy London, who recently made headlines for his drug-related difficulties, has officially joined the cast. Former model Janice Dickinson, Jason Wahler (The Hills), Leif Garrett, Frankie Lons (Keyshia Cole’s mother) and oil heir Jason Davis will be joining him - not to mention, Tiger Woods mistress #1 Rachel Uchitel. Filming on the third season was pushed back, because producers couldn’t get enough star power on the series. With additions like Uchitel, London and Garrett, Celebrity Rehab is looking positively addictive again.

No premiere date has been set, but the celebs are ready to begin their 21-day detox at the Pasadena Recovery Center, where the show has always been filmed. Wahler, who has been involved in several DUI offenses, was the first to sign up for the series. Rachel Uchitel was a tougher sell; the celebrity-by-association balked to doing the series at first. When the monetary offer for her appearance was doubled (to a whopping $500,000, TMZ reports), Uchitel finally agreed.

Uchitel was also up for a position on Donald Trump’s Celebrity Apprentice, but the infamous mistress has been fired before ever officially landing the gig. “It’s a terrible decision,” Trump said of Uchitel’s Rehab stint. “We have zero interest in her now.”

“Celebrity Apprentice is a huge show and Celebrity Rehab is not. I have ten people who want to be on the show for every slot that’s available. I’m moving on,” Trump said.

It’s true that Apprentice, a network reality show, enjoys a much larger market than VH1’s Rehab…but Uchitel, who is going to the Recovery Center to kick a bad pill habit, will receive no treatment for her drug addictions under Donald Trump’s mentorship.