"Nick Nolte voluntarily entered Silver Hill Hospital to receive advice and counsel that he feels he needs at this time," his publicist, Paul Bloch, said Monday. "He will be there as long as he feels is necessary."
Billy Joel and Diana Ross are among those who have recently been treated at Silver Hill.
Nolte, 61, checked into the center on Sept. 14, just days after he was arrested and booked for investigation of driving under the influence of alcohol or drugs.
Nolte had been driving his black 1992 Mercedes-Benz, swerving into oncoming highway lanes, when he was stopped Sept. 11 near his west Malibu home, police said.
The arresting officer described Nolte as disheveled and drooling during the traffic stop along the Pacific Coast Highway, Capt. Dan Bower of the California Highway Patrol said.
The actor was arrested about midway through a roadside sobriety test because it was clear he was under the influence, Bower said.
Results of a blood test are still pending. A court hearing has been scheduled for Oct. 28.
Nolte had a reputation as a heavy drinker for years, once describing himself as a "functioning drunk." But in the mid-1990s, he reportedly quit alcohol and became a fitness buff.
He was nominated for Oscars for 1991's "The Prince of Tides" and 1997's "Affliction." He also received an Emmy nomination for his breakout role as Tom Jordache in the 1976 television miniseries "Rich Man, Poor Man."