Robin Williams is in rehab without falling off the wagon.

"After working back-to-back projects, Robin is simply taking the opportunity to fine-tune and focus on his continued commitment, of which he remains extremely proud," his rep told People.com.

The 62-year-old actor plans to stay for several weeks.

Williams is at Hazelden Addiction Treatment Center in Minnesota in a program specifically for maintaining long-term sobriety, according to TMZ.

Williams has battled chemical dependency since he shot to fame in the late 1970s on sitcom "Mork and Mindy."

"Cocaine, for me, was a place to hide," Williams told People magazine in 1988. "Most people get hyper on coke. It slowed me down."

Robin Williams attends the CW, CBS And Showtime 2013 Summer TCA Party on July 29, 2013 in Los Angeles, California.
Robin Williams attends the CW, CBS And Showtime 2013 Summer TCA Party on July 29, 2013 in Los Angeles, California. (Jason Kempin/Getty Images)

Williams first stopped using drugs and alcohol in 1982 when his first wife, Valerie, was pregnant with their son Zachary. The idea of fatherhood and the drug-related death of his friend John Belushi prompted him to sober up.

"The Belushi tragedy was frightening," Williams said. "His death scared a whole group of show-business people. It caused a big exodus from drugs. And for me, there was the baby coming. I knew I couldn't be a father and live that sort of life."

Williams has two other children: 24-year-old daughter Zelda and 22-year-old son Cody, both with his second wife Marsha Garces.

Williams went to rehab in 2006 for alcoholism after 20 years of sobriety. He told ABC's Diane Sawyer his falling off the wagon was "very gradual."

"It's (addiction) not caused by anything, it's just there," he said in a 2006 interview. "It waits. It lays in wait for the time when you think, 'It's fine now, I'm OK.' Then, the next thing you know, it's not OK. Then you realize, 'Where am I? I didn't realize I was in Cleveland.'"

Tony Hicks provides celebrity commentary for the Bay Area News Group. Contact him at Facebook.com/BayAreaNewsGroup.TonyHicks or Twitter.com/insertfoot.