Just before dawn one morning in June, Howard Samuels, the executive director of the Wonderland Center - a private alcohol and drug rehab facility in West Hollywood, California - was standing in the spacious foyer of his Craftsman-style house, greeting his publicist, Cathy Griffin. They were about to head over to Fox Studios, where Samuels, who frequently turns up on the punditry circuit when an actor overdoses, relapses, or checks themselves in, was scheduled to discuss the recent drug bust of Tatum O'Neal and the apparent bisexuality of Lindsay Lohan on The Morning Show with Mike and Juliet

"Do you want any coffee?" Samuels asked Griffin, adding:

"I've had two cups already."

Samuels is a recovering cocaine and heroin addict who in August, at the age of 56, celebrated 24 years of sobriety. Caffeine is the only addictive substance permitted in the Samuels household. (His 38-year-old wife Gabrielle has also conquered several addictions - alcohol, crystal meth and compulsive eating.) Samuels is a tall, solidly built man with close-set green eyes, a prominent nose and lips that cover his teeth when he talks, occasionally giving the impression of missing dentures. He was wearing a grey linen Armani jacket with cuffed jeans and Converse sneakers.

"Did you see the New York Post?" Griffin asked, wrestling a manila folder from her slouchy pink leather handbag. She began to brief Samuels on the celebrity stumbles that he'd be discussing. The day before, Tatum O'Neal had been caught attempting to buy crack on the Lower East Side of Manhattan. "Originally, Tatum's story was that she was researching a role," Griffin explained. "Now she's saying her dog's death prompted the drug buy."

Griffin, who spent 30 years covering celebrities as a journalist, is also gossip columnist Liz Smith's "West Coast legwoman", providing items about the Hollywood set. When she was hired by Wonderland, the Daily News reported on the possible conflict of interest. Samuels told the paper: "We have a confidential facility. Anybody that leaks anything about anyone is automatically fired."

"Lindsay has been photographed kissing Samantha Ronson," Griffin continued, tapping a glossy nail on the kitchen counter. "Now she's supposedly selling an exclusive story to a magazine for $1m."

"That's the addiction to fame," Samuels said, looking pleased to have drawn the connection. "I mean, I have nothing against being with a woman, but it's the selling of the magazine cover. It's just another thing to fill the void."

Lindsay Lohan, who spent a month at Wonderland beginning in January 2007, is perhaps the centre's best-known patient. (Mike Tyson arrived shortly after Lohan and stayed for close to a year.) Lohan was later dismissive of her time there, saying that the staff had never treated anyone as "hardcore" as she was. Three months after leaving Wonderland, she was arrested for driving under the influence. She then entered Promises, the Malibu-based rehab centre. When I asked Griffin whether it was appropriate for Samuels to comment publicly on a former patient, she replied: "He was able to go on TV and not ever cross the line when Lindsay checked into Promises. There was a total media blitz for two weeks, and you don't get a lot of opportunities like that. He wasn't her therapist, anyway; he's the executive director."

Samuels also maintains a private therapy practice, focused mainly on issues of addiction, in the guest cottage behind his house. Griffin is a former patient. Samuels counselled her, in person and by phone, through her early days of recidivism. (One of her relapses occurred during a trip to Hawaii: "I said, 'Howard, I'm drinking a mai tai - what's the point?'") Her faith in his talents is absolute. "Howard can help addiction to be understood by the public. He can simplify it and destigmatise it. The celebrities have brought it to the forefront - he's just the right person in the right place at the right time." Samuels puts it much the same way. "You know, celebrities mirror what is happening in the rest of the country," he said, referring to the estimated 24.9 million Americans addicted to alcohol or drugs. "It's so important to get that message out... That's the struggle, OK? It's to try to educate people who think the only reason I'm going to Fox today is Tatum O'Neal!"

At the studio, Samuels sat in a corona of bright stage light. He crossed and uncrossed his legs, waiting for a producer to give him the signal to speak. A look of intense concentration came over his face as the first question was put to him through headphones. "Well, absolutely there's hope for these two," he began. "In Hollywood, the greatest curse that someone can have is to be young, beautiful, wealthy, and famous. Because there's only one place to go, and that's down."

Samuels has been treating a substantial segment of drug-addicted Hollywood for 15 years. I accompanied him to several Alcoholics Anonymous meetings - he has been attending AA for 18 years - and at every one he was greeted by people whom he had treated, or who were hoping to be treated by him. "Half of this town is in meetings," he told me, "and we're saving seats for the other half." One Sunday night, after an AA meeting in Beverly Hills that had a particularly flirtatious atmosphere - dating within the programme, though frowned upon, is known as "13th-stepping" - Samuels and I were driving down Third Street when he pointed out a small red house. "I did an intervention on a guy here," he said. He named a film-and-TV actor from the 1970s. "Remember him? He lived there with his mother. Unfortunately, you can't use his name." During another car ride, he drew my attention to the apartment building where he had staged an intervention on a more current leading man. "I've pretty much worked with everybody in Hollywood," Samuels said, listing several famous names as he guided his black Audi through a turn. "I could go on forever, you know what I mean?" Above the fireplace in Samuels's living room hangs a photograph of his beachfront wedding party: Christian Slater, at the back of the crowd, is making a victory sign with his arms in the air.

Samuels was, in a sense, a celebrity addict himself. His father, Howard J Samuels, was a wealthy businessman who founded, along with his brother Richard, the Kordite Corporation, which manufactured plastic products; he also served as under-secretary of commerce in Lyndon Johnson's administration. For the younger Samuels, using drugs was a way to rebel: "There was a huge amount of pressure to succeed, and I just said, 'Fuck you.'" In January 1970, while his father was campaigning for the Democratic nomination for governor of New York, the New York Times reported that the 17-year-old Samuels had been arrested in Greenwich Village two months earlier; he was charged "with possession of a hashish pipe and three amphetamines". A year later, Samuels was apprehended at Kennedy Airport for possession of cocaine and heroin. The scandal made the front page of the Daily News.

Samuels spent an unsuccessful year in rehab at a facility called Encounter (now closed) in lower Manhattan. Over the next 10 years, his drug abuse intensified. He stole from his mother and his girlfriend, and from wallets left in coatrooms at Park Avenue parties. He overdosed on cocaine. One morning, lacking a syringe, he slit open his shoulder with a razor blade in order to rub cocaine directly into the wound. His family staged a series of interventions and, in 1984, Samuels agreed to enter rehab again, this time at Phoenix House in Santa Ana, California.

The treatment at Phoenix House is based on what's known as the "therapeutic community" model - in the 1980s, this meant that residents, as members of a community that lived and performed chores together, were expected to challenge, badger and often verbally or physically humiliate one another. (The approach, sometimes called "attack therapy", was intended to wear down a patient's defences, but has fallen out of favour. Phoenix House now employs a less punitive version.) Samuels says he shared a room with 25 other men, who showered en masse. He was hollered at, made to wear dunce signs and forced to scrub toilet bowls with a toothbrush. During his stay, his father suffered a fatal heart attack, and Samuels, released to attend his funeral, experienced a "psychic shift": "I realised I did not want to die a drug addict. I did not want to be buried with the epitaph, 'He Had Potential'." Samuels completed the 18-month programme and then went back to school, eventually receiving a master's degree in psychology from Antioch University and a doctorate in clinical psychology from Ryokan College, in Los Angeles - an accomplishment he's particularly proud of because he suffers from dyslexia.

In 1994 he went to work at Promises, in West Los Angeles, first as a counsellor and later as the programme director. In 1997 Samuels was part of a team that helped the founder, Richard Rogg, set up the centre's luxurious Malibu campus. Many of Hollywood's high-profile patients of the past decade have been treated at Promises Malibu - Ozzy Osbourne, Robert Downey Jr, Andy Dick, Ben Affleck, Charlie Sheen, Matthew Perry and Britney Spears among them - and it was there that Samuels began to build the client base for his private practice and to form his own ideas about rehab. "At Promises, you know, we built a beautiful place under the philosophy of: 'Let's seduce them into treatment; why punish them by having them go to a dump?'"

That philosophy represented a departure from traditional methods of rehab, even for celebrities. Twenty-five years ago, when Elizabeth Taylor checked herself into the Betty Ford Center, seeking treatment for an addiction to Percodan and alcohol, she shared an austerely furnished room with a roommate. She took her meals in the cafeteria, waited to use the communal phone and performed the "therapeutic duties" required of all patients (bed-making, coffee-making). "We really believe that good treatment is the same for everyone," John Schwarzlose, the CEO and founding director of the Betty Ford Center, said of the programme's egalitarian ethos, which still holds, to this day.

The programme at the Betty Ford Center has its origins in the Minnesota Model, a therapeutic approach rooted in AA's 12 steps and developed in the 1950s at Willmar State Hospital, a psychiatric institution in Minnesota, by psychologist Dan Anderson. At the time, alcoholism was widely considered a failure of will; alcoholics were institutionalised, incarcerated, or left to sink into indigence. Anderson believed that addiction to alcohol (and other drugs) was a "multifaceted illness" ("physical, psychological, social and spiritual"), and sought to develop a more humane treatment. His method required a team of professionals - psychologists, psychiatrists, physicians, spiritual counsellors, nutritionists - and a minimum inpatient stay of 22 to 28 days. In 1961 Anderson moved to Hazelden, a rehab clinic in Center City, Minnesota, and over the next 20 years his model became standard at treatment centres across the country.

By the 1980s, insurance companies intent on containing costs began to suggest that the Minnesota Model was excessive. They maintained that there was little evidence that residential treatment was any more effective than a less expensive outpatient version. (Many plans now cover only outpatient treatment, or limit inpatient stays to three to seven days.) According to the Treatment Research Institute, nearly half of all residential treatment centres in the US have closed since the early 1980s. In the late 1990s, luxury rehab centres, catering to self-paying patients, began to proliferate. Today, with a 21-mile coastline and a population of roughly 13,000, Malibu alone has 29 licensed rehab establishments. Many are operated out of palatial estates; most are for-profit, do not take insurance, and expect their fee, sometimes as high as $68,000 a month, to be paid up front. (Hazelden and Betty Ford, both non-profit clinics, charge $26,000 and $24,000 for 28 and 30 days respectively, and accept insurance.)

Samuels and his wife founded the Wonderland Center with Bernadine Fried, the clinical director, and her husband, Alex Shohet, in early 2006. Wonderland charges $48,000 a month for a shared room and $58,000 for a single room, and does not take insurance. The usual length of treatment is 30 days, although, unlike most rehab clinics, Wonderland will allow shorter stays, sometimes of a week or two. On occasion the centre offers scholarships. I witnessed Samuels arrange a scholarship for a woman I'll call Greta, a singer from an early-90s band, after he heard her speak about her 15-year struggle with heroin addiction at an AA meeting. ("I'll do your shit work - I'm just having a hard time and really need some help," she told him.)

Like many rehab facilities, Wonderland bases its treatment on the principles of AA. But Samuels and Fried assert that their establishment offers a uniquely "individualised" programme. Residents are permitted to use mobile phones and computers, for example, and many continue to conduct business during their stay. They are taken on shopping trips and are allowed to bring their dogs. Actors are sometimes released to work on films; musicians can travel for tours.

Many treatment professionals argue that granting this much licence to addicts is no way to treat a condition that Bill Wilson, the co-founder of AA, described as "self-will run riot". "Addicts need frustration; they need limits; they need structure. They need to learn how to tolerate those things," Dr Drew Pinsky, the service director of the well-regarded rehab programme at Las Encinas Hospital in Pasadena, said. "The more you cater to an addict's demands, the more you support their disease. Our approach at Las Encinas is: 'Get with the programme or get out.'" John MacDougall, the director of spiritual guidance at Hazelden, told me: "No one leaves here - except for a funeral, if a close relative dies. We ask you to commit for 28 days. Actually, I can only remember one exception in the 14 years I've been here, and he had to present a treaty at the United Nations."

The Wonderland Center occupies a $7m property on Mulholland Drive. Behind a massive iron gate, three cream-coloured houses with terracotta roofs are set back from the road by a long, winding path that staff members navigate with golf buggies. The bedrooms are simple, with crisp white duvet covers and wooden armoires. (There are only six single rooms, because clients often have, in the parlance of Wonderland, "a tendency to isolate".) There are two small kidney bean-shaped pools and two sprawling patios. Here, between sessions, clients lounge on wrought-iron furniture and talk and text and smoke. One has the overwhelming sense of attending a weekend party at a cosy but understated house.

Late in the afternoon on the last Friday in June, Wonderland's eight in-residence patients - the centre has 14 beds, but the summer months are slow - had completed their Bridging Mind and Body group session, in which they had written letters to themselves ("Remind yourself what skills and abilities you have, what you are good at...") and enjoyed a lunch of grilled lobster tails with garlic butter. Every morning the residents, whom the staff refer to as "clients", are woken between 7.30 and 8am. They meditate, eat breakfast and exercise, either performing yoga poses with an instructor who comes to Wonderland, or working out at Crunch on Sunset Boulevard under the supervision of a Wonderland employee. During the day they attend two or three group sessions - Anger Management, Sex and Love Addiction, Music Therapy - and in the evenings they are driven to an off-site AA meeting. Samuels declines to push AA on resistant patients, though he says that most will relapse "until they finally surrender to the reality of doing it through AA".

Around three o'clock the clients, along with several day patients, began taking seats in the large living room for the last group session of the week, the Beast, which is run by Samuels. "The Beast," Samuels told me later, "is the drug, the alcohol, the unavailable man, the depression. It is that self-destructive energy that destroys us, which we can't stop." Samuels lifted a glass of iced tea - "Cheers, everybody!" - and called the session to order. Dressed in a pink button-down shirt, the cuffs undone and the collar open to reveal greying chest hair, he began to pace back and forth. "The great news is that it's Friday, right? So what does that mean? That means that tonight you're still in rehab. That means there's no drinking tonight, no crack pipe tonight, no little line of blow, no pills, no weed."

The clients, looking drained at the end of a long week of self-scrutiny, laughed ruefully. Samuels went on: "But you're still going to be dealing with the Beast, OK? Because the Beast is going to tell you that it's Friday night, and it's time to get loaded! I gotta say, normies have that voice, too." "Normies", or non-addicts, are frequently invoked by the residents of Wonderland as an impossible ideal; normies are thought not to suffer from pain or depression or obsessions. Samuels is fond of reminding people that he is not a normie - "Howard Samuels: dope fiend, convicted felon," he routinely announces.

"Who has a Beast?" Samuels asked, scanning the room.

Max, a college professor of finance who was at Wonderland to kick a five-year pill-and-cough-syrup habit, spoke up from the far end of the sofa. "You know, I have a pretty empty kitchen," he said, "and when parents and friends ask me why, I say: 'Because if I had anything in there that I liked, I'd eat the whole thing.' I can't go buy a package of Oreos because I'll eat it in one sitting. That's the Beast, too. I can't just take one Oreo. I'll go back and I'll go back and I'll go back. It's not a drug but it's... out of control."

"Well, you know, Max, you're obsessive-compulsive, and the obsessive-compulsiveness isn't just centred around drugs and alcohol," Samuels said. "Once you get sober, you're still going to be obsessive-compulsive. But I'd much rather have you deal with not being able to stop eating Oreos than not being able to stop... what's your drug of choice?"

"Opiates."

"Opiates, OK. Let's move out the opiates - I'm happy with the Oreos." But Max did not look happy. He was clearly disturbed by the Oreo obsession. Samuels went on: "Now, once you get to be about 200 or 300lb, we'll have to deal with that. We'll send you to an Oreo 12-step meeting, all right?" Max mustered a chuckle.

Samuels uses an avuncular, teasing sense of humour to draw people out. Several members of the LA recovery community told me they felt he did not maintain sufficient professional boundaries - that it was inappropriate, for instance, for him to frequent the same AA meetings as his patients. One woman recalled seeing him whizz down the street in her neighbourhood: "He's got a patient in the passenger seat, and is test-driving the patient's new $100,000 Mercedes." But I was told by an entertainment executive who is being treated by Samuels for his cocaine habit: "He cuts through the bullshit; he's not playing footsie."

Samuels took a gulp of tea and continued pacing. "Who else?" he asked.

Nicole, a young woman with dark, sad eyes and strawberry-blonde hair pulled into a loose ponytail, spoke next. "My Beast says that it wouldn't really be a big deal if I had a drink today," she said, in a voice so soft the others in the room had to lean forward to hear her.

"Let me ask your Beast some questions," Samuels said. His tone was gentle, not jesting.

"What was your drug of choice?"

"Alcohol."

"How often did you drink?"

"Every day."

"What was your drink of choice?"

"Anything."

"How much would you drink during the day?"

"I'd have two bottles."

"Two bottles of what?"

"Vodka or rum."

"And how long did you do that for?"

"Four years."

"And how old are you?"

"21."

"So when did you start drinking?"

"When I was 17."

"When you were 17. And you were able to not go into treatment until you were 21, huh?" He lowered his voice further.

"Yes."

"Wow. Do you think that that's normal?"

"No, but I think that... I think I can control it now. That's what my Beast says." As basic as Samuels's premise is, the metaphor seems to give the patients a way of talking about their addictions.

"And I want to ask your Beast: have you ever been able to control it?"

"Sometimes..."

"Right, but how many times?"

"Not that many."

"Now, did some horrible things happen to you when you were drinking?"

"Yeah..."

"So why would you want to drink? I mean, think about it: if horrible things happened to you because of alcohol... and you got locked up in treatment, ruined relationships, ruined years of your life, why would you want to risk all of that for a liquid?"

"I just miss it." Nicole looked down at her lap. Three of the women in the room began to weep softly. The only other noise came from the adjacent kitchen, where the chef, Chris Wilson ("Tom Hanks's brother-in-law," Cathy Griffin informed me), was shredding carrots for the evening's salad.

Later that afternoon Marvin, an 80-year-old cocaine addict who had been at Wonderland for three weeks, agreed to show me his room. A bakery box containing a dozen cupcakes sat on his desk ("So I can give them only to who I want to have them"). After his wife died several years ago, Marvin took up with a much younger woman who turned him on to cocaine. The Wonderland staff set him up with a team of doctors at Cedars-Sinai hospital who examined his heart, which can be strained by cocaine use. (I later observed one of the Wonderland staff members helping Marvin navigate Matchmaker.com in the hope of finding him a non-enabling girlfriend online.) I asked Marvin whether he felt he had recovered.

"I'm already a recovering optimist," he joked, deflecting the question. "My problem was depression - the drug was incidental. I don't do the 12-step programme. I don't go to the AA meetings. I don't need it. Yeah, and I needed a vacation anyway."

At dusk, as dinner wound down (Chilean sea bass with plum syrup, mini lamb meatloaves with mint), a few of the clients lingered on the patio. A ghost of a girl, with troughs the colour of bruises beneath her eyes and track marks up and down her arms, could be heard on her mobile phone, crying. Earlier that afternoon she had staggered over to me, a long silk scarf tied around her neck, and said that she was horribly "dope sick" and had spent the previous night at the hospital. This was her second visit to Wonderland. Nearby, a lanky young woman with dyed-blonde hair was talking to a guitarist from an 80s pop band. "I'm on Suboxone now," she told him. (Suboxone is commonly used instead of methadone during heroin withdrawal.) "I'm coming off it. I've been through it before, but I'm scared."

Wonderland's co-founder, Bernadine Fried, met Samuels while lecturing on addiction at Antioch University. Both worked for a time at Promises before leaving to start their own practices. "We developed these private practices and were really, you know, wildly successful. But we both missed working in a treatment environment," Fried said. Fried is 46 and has been sober for 20 years. Like Samuels, she is a former heroin addict; her husband, Alex Shohet, was once her dealer. Shohet suffered a relapse in 2000, but has now been sober for four years.

There has been tension among Wonderland's founders from the time the centre first opened its doors. Samuels and Shohet clashed over the question of who should act as CEO, as well as over a "sober living" facility that Samuels was running out of one of his four homes. Shohet and Fried felt it was a violation of their non-compete agreement. (Samuels's neighbours were also upset. "There were all these people going in and out of the house, and up all night, and this is a very residential neighbourhood," one of them told me.) By December last year, Samuels, Shohet and Fried had begun attending "business therapy" together once a week. When that didn't help, they hired Andrew Spanswick, a social worker with a background in hospital management, to act as CEO. He was unable to resolve the dispute, and the partners agreed that each side - Shohet and Fried on one; Samuels and Spanswick on the other - would begin raising money to buy the other out.

On a Thursday morning in late June, I met Bernadine Fried, who has dark wavy hair and a gentle manner, at a ranch in Malibu, where she led a weekly session for Wonderland patients known as "equine-assisted psychotherapy" (an offering at many high-end treatment centres). During one of her sessions, clients would spend time with the ranch's five horses - grooming or feeding them, sometimes even painting on the horses' sides with watercolours. "I'll say: 'Paint something from your past, present, or future. Do half the horse from your past, half the horse from your future,'" Fried explained. (For the more apprehensive patients, there is a miniature donkey named Waffles.) The therapy is said to have originated in Denmark in the 1950s; horse riding, or hippotherapy, was believed to alleviate the physical effects of diseases like cerebral palsy and polio. Today the idea seems to be that simply being around a horse can confer psychological benefits and that horses can reveal a patient's unexpressed emotional states - reacting to feelings of fear or anxiety or aggression by whinnying, say, or by stamping their hooves. "Horses are able to read energy," Fried told me. "They are incredible therapists. I let them show me what's going on with a person."

Fried claimed that the method was especially useful with clients who were hardest to reach by traditional means: those with a history of trauma or who had repeatedly failed at recovery. These patients are the reason she founded Wonderland. "I would have, like, the relapsing heroin addict that's been in rehab 12 times, and I'd think: 'What am I going to do with you? I have nowhere to send you,'" she said. Wonderland's patients also tend to be wealthy, and therefore to have considerable resources for masking their addictions. "Most people are like: 'I totalled my car - I'd better go into rehab,'" Fried said. "These people are like: 'I totalled it - I'll get a new one, or I'll drive the Porsche today.'"

Several of the patients I spoke with complained that Wonderland affords unfair privileges to its wealthiest or most famous residents. Mike, a commercial real-estate broker and recovering cocaine addict who was an outpatient at Wonderland in January 2007, described the hoopla surrounding a celebrity client - paparazzi circling the property, spectators at Wonderland's regular Thursday-night AA meeting. "To have a little entourage with you in rehab is... it was crazy," he said. "The driver sat outside. The publicist hung out with the driver or the personal assistant. People were in and out and coming and going. It was chaos."

During Lindsay Lohan's 30-day sojourn at Wonderland, her many comings and goings perplexed the tabloid media. There she was in the lobby of her apartment building, on the set of her film I Know Who Killed Me, taking her SL500 to Beverly Hills Mercedes to be serviced. "Does the treatment involve the attending of Mad Tea Parties and the chasing of white rabbits? Maybe for Lindsay, but not for anyone else in residence," one blogger wrote. "I even had that conversation with Howard," Mike told me. "I said: 'Well, I think some people are a little bothered that their programme and their stay at Wonderland is being negatively impacted by this craziness and why rules don't apply to her that apply to us. I mean, there is some resentment building up.' And he said, 'You know what, Mike, I hear you, but we have to cater our programme and our treatment centre to each individual to make it work for them. Because if we didn't do that for this individual, she would have been gone on Day One.'"

The following Monday, after an art-therapy class in which clients painted wooden birdhouses and trimmed them with pompoms and pipe cleaners, the objective being to "create a home" for themselves (Max: "What's the sobriety angle on this?"), the group gathered to celebrate the third "sober birthday" of Susan, the health-services co-ordinator responsible for distributing client "meds", with a round of singing and a key-lime pie decorated with candles.

The previous day Greta, the 1990s-era singer, had been allowed to leave the centre to perform the national anthem at a sporting event. (For any off-site business, Wonderland supplies residents with "sober companions" - Wonderland employees, who are usually introduced as a friend or a cousin from out of town.) It had been a month since the AA meeting at which Samuels first met Greta. Her hair, formerly unkempt and mousy, was now layered into a modern mullet and dyed a variegated blonde and brown. Her nails were painted in a punk-rock French manicure: blue with black tips. (The staff at Wonderland had arranged for her to have her hair coloured, and had also driven her to get her guitars out of the pawn shop.)

"How was it yesterday, singing sober?" someone from across the table asked.

"Ah, dude, it was really amazing," Greta said. "It was the first time ever. Once I had 90 days and I booked at the Knitting Factory on a Wednesday, which is, like, when no one is there, and I showed up and there was, like, 30 people there to see me. I was like: 'Who are all these fucking people?' I thought: 'Oh. My. God.' So I went and did a shot of vodka." The discussion came to a halt when Susan materialised at Greta's side.

"You need to come take your meds," she told Greta. Though its residential-rehab licence stipulates that Wonderland's staff cannot administer medication, they watch to make sure the patient swallows it. Nearly all the clients are on some type of medication, whether for detoxification (such as Suboxone, for opiate withdrawal) or to treat an underlying psychiatric disorder (Zoloft for depression, Klonopin for anxiety).

"I can't take them without having something to eat,"

Greta replied.

"You didn't come at breakfast."

"I know, but I was in the shower, and then I was late for group."

"You were late yesterday. After you finish eating, I need you to come take them." Susan was calm but firm.

"This attitude isn't making me want to do it," Greta said.

"But it's also, like, the ninth time since you got here that I've had to remind you..."

"OK, but the attitude is not helping me."

"Well, it's getting a little bit old. I'll do the best I can to help you, but it's getting to the point where it's your place to remember." Susan walked away, the keys to the medication storage room jingling from her belt.

"You all right?" a lunch companion asked Greta.

"It's all right. She's right," Greta conceded. "It's just the attitude; it's always like that."

In August, Wonderland celebrated its second anniversary. The centre has treated approximately 240 clients and employs an "alumni co-ordinator" who keeps up with them: sending cards for sober birthdays, tracking changes of address. He does not, however, track Wonderland's success rate. This may be because residential treatment programmes have abysmally low rates of success - from about 10 to 30%, depending on where you get your statistics. Or it may be because Wonderland is still so new that any statistics would be meaningless.

Dr Steven Jacobs, an internist and addiction specialist who has served as a medical consultant to Wonderland, told me: "Twenty-five years ago, when I first started, the notion was that if you stayed abstinent for two years, you would have a 90% chance of staying clean and sober. Now the disease is thought to be more pernicious. It isn't until a person has had about five years that we think it's really likely they'll have a lifetime success of staying sober, from a scientific point of view."

Even established clinics don't offer much in the way of useful statistics. "Do we know what our relapse rate is? No," Betty Ford's John Schwarzlose said. "We know that our physicians and dentists do well, at about an 80% success rate" - these doctors, who are monitored for five years after completing treatment, must pass random urinalysis tests or lose their licence, so the incentive to stay sober is high - "but to give you a percentage would just be pulling it out of the air." Hazelden, which claims a success rate of between 53% and 56%, tracks the abstinence of its patients for only one year.

On the Saturday morning after the Fourth of July, I met Samuels in the small guesthouse where he sees his private clients. His grey hair had recently been cropped close, and he was doing the Master Cleanse, which meant he had consumed nothing but lemon juice, cayenne pepper, maple syrup and water for five days. "I like doing it because I'm sort of an extremist, you know? I think it builds your sense that you can do anything you set your mind to," he said. Samuels's wife Gabrielle could be glimpsed through the window in a maroon bikini with blue trim, sunning herself alongside the extra-wide lap pool in the backyard. "Success rates are bullshit," Samuels told me said. "The first time somebody goes to treatment, yes, the success rate is low... but I failed after my first treatment, OK? So does that mean I'm a failure?"

The ringing of his office phone interrupted him. It was one of Samuels's regular clients, an actor and former cocaine addict in his late 30s who, while on location, had cheated on his wife with his 23-year-old co-star. Samuels counselled him for several minutes; I petted Hank and June, the Collie-Lab-German-Shepherd mixes who had left their olfactory imprint on the office. "I think without question you're a good person," Samuels was saying, stressing his syllables with care, "but you have character defects and you have self-destructive aspects that, you know, you're not in control of yet..."

When he hung up, I returned to the question of recovery.

"It really is about the willingness of the client," he said. "That's going to be the key to long-term success. I'm not a believer that treatment centres save people's lives. I think if you've got a really good treatment centre you can go a long way toward helping a person, but at the end of the day it's not about the treatment centre. It's about the individual, and about whether or not they're at that place to change."

The Wonderland Center recently underwent an organisational overhaul - several employees were fired, including Bernadine Fried. Samuels and Spanswick were able to terminate her contract because together they formed two-thirds of the board. (Alex Shohet was let go last April; Shohet and Fried, who still own a 49.5% share of the company, are planning to seek an injunction to reverse the takeover of Wonderland by Samuels and Spanswick.) "I wanted a new start," Samuels said simply, referring to the changes. Samuels and Spanswick now have ambitious plans for Wonderland's expansion, the first step of which is to open an outpost in New York City. They imagine that New York clients will appreciate a programme that allows them to receive treatment while continuing to work. From there, the partners plan to move on to additional cities by acquiring existing treatment centres and remaking them according to the Wonderland model. Samuels considers rehab a recession-proof business. "We're looking to expand the sober community," Samuels said. "To get the message out that it's cool to be sober, that your life isn't going to be a drag, that you can kick ass and have an amazing life - you can take over the world."

• All clients' names have been changed to protect their privacy