Actor Eric Roberts, Julia Roberts' older brother, is joining the cast of VH1's Celebrity Rehab 4, RadarOnline.com reports. Roberts, 54, has moved into the Pasadena Recovery Center. No word on what Roberts is getting treated for though he was arrested in 1987 for cocaine possession and allegedly battled a cocaine problem into the '90s.

The actor was most recently seen onscreen in 'The Dark Knight' and was nominated for an Oscar in 1985 for his role in 'Runaway Train.' He also had a recent recurring role on 'Heroes.'

The 'Celebrity Rehab' cast also includes reality TV star, Jason Wahler, Tiger Woods' mistress, Rachel Uchitel and 'Party of Five' star Jeremy London.