Just over a week ago, around 50 people gathered in a small conference room in a hotel in west London to hear two former drug addicts speak. John Southworth and Ken Seeley both run their own interventionist companies in the US and are here to train people in the tactic – effectively, taking a person with an addiction (drugs, alcohol, gambling or any kind of compulsive behaviour) and putting them in a residential rehabilitation centre.

Interventions have a higher profile in America ("The UK is going through what the US did many years ago," says Southworth), largely thanks to a reality television show called Intervention, in which Seeley starred. Last year, the series won an Emmy award but it has also been criticised for exploiting vulnerable people, because the tactics Seeley and Southworth describe are so tough – people have been thrown out on the street to see how they cope once their family are encouraged to stop "enabling" their addiction; others are chased by the camera as they try to run away.

"You can lead a horse to water but you can't make it drink," says Southworth, "but we can make it damn thirsty. It's about creating consequences." This can be anything from threatening a person who has stolen from their family with reporting them to the police, or making them realise that without getting help for their addiction they could lose a professional licence (if, for example, the person is a pilot, or a nurse). "Our job is to work out what is going to be the consequences that will get them thirsty," says Southworth.

"I had [a client] who waited three days. She slept in the street," says Seeley. Doesn't it worry them that vulnerable people are being put in a potentially dangerous situation? "Yes," says Southworth, "but if nothing else works, what are you going to do? It's called tough love." If they believe someone is genuinely in danger, says Seeley, "we have police checking on them, or a private investigator or interventionist in visual contact with them."

In the UK, there are relatively few professional interventionists.Bill Stevens, a former addictions counsellor for the Priory group of hospitals, set up his company Red Chair two years ago and feels that "it is bound to grow". Stevens has carried out around 45 interventions. Would he advise a family to throw the person with an addiction out on the street? "An intervention should be based on love and dignity. Why chuck a sick person out on the street? I think the idea of intervention being aggressive . . . it should be the opposite."

One of the main aims of the conference, he says, was to set up a self-regulating body in the UK. There are people, he says, who work on a type of commission, paid by private treatment centres to essentially feed patients to them. "If you are paid a referral fee then you are in a huge ethical dilemma," he says, adding that Red Chair charges the family for the intervention – usually around £750 – not the treatment centre.

"A family member will ring up and say their loved one has a drug or alcohol problem and I'll work through the pre-intervention screening process: is it right to do something, who is affected, what are the consequences, what will happen if you do nothing? It's about treating the family as well, so they can help someone go to treatment and then support the person after treatment."

Then he will often bring the family together with the person and ask them to go into treatment. Faced with that, he says, very few refuse. In most cases, the person is treated privately, but for those who can't afford it, Stevens assists them to go through the NHS process.

Paying for an intervention is partly what worries Andrew Horne, director of operations in Scotland for the addiction charity Addaction. "Every single person in the country has the right to an NHS community care assessment," he says. "From that, they will assess what those needs are and devise a care plan. I have a little bit of concern around interventionists in that I know people who have paid for residential private care when really they couldn't afford it, but they did it because they felt they were desperate. They didn't know they could have got that for free. [Intervention] is very much an American model becasue of the American healthcare system, which is pay as you go."

If there is a fault in the system, he says, it is in not making people aware there is help out there. "In England the system is fast – the target is to go from referral to treatment in three weeks." (Scotland is a little behind that.) But don't people use interventionists as a last resort? "The idea of working with involuntary clients is not alien to most drug charities and treatment systems," he says.

Horne is also concerned about the reliance on residential treatment. "There are fantastic services in the community and while people like residential care because it gives a certain amount of safety, the efficacy of that care is sometimes not as good as if they remained in the community. Placing someone in residential care means they still have to return to their lives."

A vast proportion of interventionists are former addicts themselves. Stevens went into treatment for his addiction 17 years ago. Seeley was addicted to crystal meth, Southworth to cocaine; both have been clean for more than 20 years. "I'm in recovery. I've been there," says Southworth. "An addict can't lie to another addict. They know we've been there. I don't want people to go what I did – jail, job loss, family loss." Many interventionists are fuelled, he says, by a desire not to allow other people's lives to be ruined by addiction. Whether it will work here, or not, is too early to say.