MALIBU, California -- Whether it's thanks to Britney or any of the other dozens of celebrities who have sought addiction treatment in recent months, "going to rehab" is now a frequent phrase in our vernacular.

But what exactly does it mean?

Rehab can describe a variety of things, but when it comes to the rich and famous seeking help, it tends to come from fancy facilities near their neighborhoods in Malibu, such as Promises, where Spears was recently photographed (see [article id="1552993"]"Britney Back In Rehab Yet Again"[/article]).

To get an understanding of the experience of entering one of these resort-like treatment centers, MTV News toured Passages Addiction Cure Center, which has housed several celebrities since it opened in 2001. (It's against federal and state law for facilities to reveal the names of any past or current patients.)

(Find out what rehab is really like in this video tour of Passages.)

At Passages, most patients enter voluntarily, although some come at the insistence of parents or a spouse, according to co-founder Chris Prentiss. Passages primarily treats drug and alcohol addictions, "but also sex, gambling and compulsive behavior of any kind, including overeating and undereating," Prentiss said.

Out-of-town guests, which make up most of Passages' 29 patients, are picked up at the airport by a limousine because "feeling nurtured and cared for is one of the processes," Prentiss said. Upon walking into the marble-floored corridor, patients are warmly greeted and taken to an intake desk where general information is gathered, such as their dietary preferences. At Passages, blood is also drawn.

"Everyone struggling with an addiction has a chemical imbalance," Prentiss explained. "We see where that is coming from so we can correct it for them, which will immediately bring relief."

While this is going on, the patients' luggage is searched for alcohol, drugs and prescription medicines. Cell phones and Blackberrys are allowed. "We don't want people to be out of communication with people they love or need to talk to," Prentiss said. "We encourage visitors. We have a program where family members come in to the one-on-one sessions."

Past celebrities have brought assistants and even maids with them, but there are no overnight guests and no bodyguards since security is provided by the facility, which is behind two gates and under 24-hour surveillance.

After intake, patients are ushered to their rooms, which resemble the average hotel room, with slightly bigger bathrooms. About 95 percent of Passages' patients share a room, although private rooms are available for an additional $22,500 for 30 days. A shared-room stay is $57,550 for one month.

Within four hours of their arrival, patients at Passages are in a one-on-one session with a therapist in a private room equipped with two lounge chairs and sometimes a massage table (not couches).

Different rehab centers have different programs, but at Passages, it's mainly one-on-one sessions (65 during a 30-day stay) with 10 different therapists, who meet each week to individually structure the following week's sessions. Facilities that use 12-step programs focus more on group sessions.

Passages also has life-purpose coaches who take patients outside of the facility on hiking, kayaking or mountain-biking trips. "People who are obsessed with drugs and alcohol lose their purpose in living," Prentiss explained. "So we reawaken that joy for life and re-establish in them some passion."

All sessions are mandatory, while social activities in between are optional. (There's a sign-up sheet for manicure/pedicures at the front desk.) This facility has a 7:30 a.m. wake-up call and an 11 p.m. curfew, with meals served at regular times throughout the day.

At Passages, the chef comes from Wolfgang Puck's Spago restaurant and cooks elaborate organic meals catered to patients' preferences. Thai tuna rolls were being prepared as MTV News toured the kitchen.

It's not a lockdown facility, but Prentiss said the majority of patients stay for 30 days. On the final day, there's a graduation ceremony in the oversize living room. "They sit in a big circle and share stories and say goodbye," Prentiss said. "A lot of crying goes on." (Passages also hosts reunions every year, where past patients return.)

Overall, Prentiss insisted that the celebrities who come to his center have the same kind of experience as average Joes (although due to the cost, average Joes tend to be CEOs or privileged children), and many share rooms.

"Celebrities may be different with their loss of privacy and the adulation they are used to, but their problems are the same," Prentiss said. "They have the same childhood conditions, the same current conditions."