You don’t have to survive a personal journey to hell and back to become a motivational speaker in schools, but it does help.

Keith Warren endured divorce, depression and a nervous breakdown before deciding he wanted to change young lives for the better. Now he works with more than 120 schools, helping pupils to try harder, stop being disruptive, or to aspire to greater heights.

The misfortunes of fellow speaker Richard McCann, meanwhile, are enough to make you wonder how he gets out of bed.

His mother Wilma was the first of the Yorkshire Ripper’s 13 victims just a week before Richard’s sixth birthday, in 1975. After being placed briefly in care with his sisters, they were returned to their violent, alcoholic father, who beat them with sticks a foot long and drowned the family dog in the bath.

After a childhood lost to deprivation, violence, grief and criminality, Richard left school at 15 with no qualifications. He hit rock bottom after serving a prison sentence for drug dealing and entered a suicide pact with his elder sister Sonia. But that proved a turning point: “It was only when she took an overdose that I realised I had to live, to be strong and help her to live,” he says.

To most of us, motivational speakers conjure up images of oily, shiny- suited cliche-merchants reminiscent of The Office. But a small market has sprung up for motivational speakers in schools, in spite of their often considerable cost. So what value can they add?

Both Richard McCann and Keith Warren are regularly brought back to schools for repeat visits, and have been judged to have made measurable improvements to the attitude, behaviour and exam performance of pupils across the range of abilities and expectations.

Diana Boulter, of speakers’ agency DBA, says Simon Weston, the Falklands War survivor who put his life back on track after recovering from horrific burns, has been brought back as an inspirational speaker five years running at Wood Green High School in Wednesbury, West Midlands.

Typical fees for specialist motivational speakers for schools range from pound;500 to pound;1,000 per half day or full day, sometimes including workshops as well as the main presentation. Yet even schools in deprived areas with tight budgets have deemed this to be money well spent.

For Keith Warren, getting pupils to take in “the big picture”, as he calls his presentations, involves giving them the insight to take responsibility for their future. They need to realise that if they want to fulfil their future ambitions, they have to do things differently now.

First they tell him what’s “cool” now and what would be cool for them as adults - a good job, nice house, smart car and so on. But the penny soon drops that behaviour and attitudes which may seem cool today will not necessarily make them happy in the future.

“The kids think that Michael Jackson or Lewis Hamilton or Kylie Minogue or Fernando Torres became famous overnight,” says Mr Warren. “Unfortunately that’s not true. Michael Jackson was training to be Michael Jackson from the age of four, Lewis Hamilton was go-karting at the age of seven, and you can’t become a Fernando Torres by deciding to learn football at 17.”

Betty Hasler, who until Christmas was interim head at Grantham Technology and Sports Centre, felt that, eight months after Mr Warren’s visit, the school’s GCSE results spoke for themselves, even though his presentation was not the only factor in enhancing the pupils’ expected performance.

“We had a cohort of pupils in Year 11 who really didn’t feel very motivated. We were concerned about them - they were quite disaffected, but Keith raised their aspirations and made them more motivated,” she explains.

“We did all sorts of things afterwards, too; working with each of them and their parents. We got them to look at what their predicted results ought to be, according to their ability, and regularly tracked how they were doing.

“Keith came back on results day, and of that particular cohort, when we first assessed them just over 20 per cent of them were likely to get the required five A-Cs at GCSE, including English and maths, and we ended up with 40 per cent getting it. We think that was down to a combination of what Keith did and what the school did.” Mrs Hasler was over the moon; the school enjoyed its best ever results.

The pupils themselves don’t quite know what to expect. They tend to drift in, Mr Warren says, expecting to be bored by someone talking at them, rather than to them, for two hours.

Mr Warren wrong-foots them immediately, deploying music, showmanship, stories, humour and interactive games to engage them. It’s a formula that works time and time again. And since most of the feedback Mr Warren gets from teachers and pupils is so positive, he can afford to acknowledge the occasional dissenting voice.

“One pupil the other day, his name was Javad, said: `You’re a fraud and a preacher.’ So I said to the year group: `He’s very brave to say that, but that’s not true .’ And I said to him: `I’m sorry if you think I’m preaching, but I’m not. I never preach. I never tell pupils what to think or what to say.’”

Yet after the talks, the pupils are so convinced by his rhetoric that they write down pledges to `be better’ - anything from `I will try harder’ to `I will believe in myself more’.

Most teachers agree that quantifying long-term effects of such visits can be difficult, but when TES Magazine approached a number of schools that had booked Richard McCann or Keith Warren, every one of them gave a positive report. One school’s responses included pupil promises to “eat healthier” and “apply for an audition at the National Youth Theatre”.

Reactions to Mr McCann were emphatic. John Williamson, head of the One- Year Sixth Form at North Leamington School, Warwickshire, says: “I’m in charge of some of the more difficult sixth-formers, and I met the father of one before Christmas and I said `You’ll be getting his Christmas presents ready’.”

He said the only present his son wanted was “the book by the guy who came to the school” (Just A Boy, Richard McCann’s bestselling autobiography). It was sold out everywhere in Leamington. I couldn’t believe it.”

North Leamington School is housed in a new pound;32 million campus which, despite a mixed intake, could not be farther from the sink estate comprehensive that Mr McCann attended. It is not just schools that struggle to get good exam results which look to motivational speakers for inspiration.

Jim Rutherford is a Year 11 pupil learning co-ordinator of Tomlinscote School in Frimley, Surrey. It’s a high-achieving school in a leafy suburb - only three of the 270 pupils are on free school meals, and 40 per cent of pupils get eight or more A*s at GCSE.

“It’s not unusual for us to have high achievers here, but the biggest problem that we face is apathy,” he says. “Many of them are the children of self-made people, they live comfortable lifestyles and the motivation for them to do well on their own behalf is not always as strong as it might be.

“In pursuit of giving pupils every possible stimulus to do as well as they are predicted to, we looked around and I watched Keith Warren’s promotional video. I thought: `This guy looks like he might just be able to get their attention.’ Bringing in somebody from the outside makes a difference. Me saying it is just what they would expect me to say.”

Mr Rutherford also liked the notion of pupils recording their targets on a postcard, and then being reminded of those targets in a follow-up mail later on.

Mr McCann says that measuring exam performance is only part of it: “I’ve got some statistics from feedback immediately after my sessions and 86 per cent of the audience said they were either more inspired to go on to university or would take education more seriously.

“But I think my approach is much more than that; it’s about life skills, how to deal with those hard knocks that come along; it’s about applying that positive mental attitude and mixing with the right people.”

Financing these sessions can be difficult. North Leamington School had a business benefactor to thank for meeting the bill, while the Dukeries College in Ollerton, Nottinghamshire, a deprived former mining area, used funding from Aimhigher to bring back Richard McCann for a second visit. Lyn Davidson, head of house at Sir Graham Balfour School, Stafford, had to pull out all the stops to pay Keith Warren’s pound;800 fee. “We had to bring in support funding from the PTA and Aimhigher, then pupils paid a couple of pounds each towards it, so costs were a bit tight, but the immediate, short-term response was positive.

“They came out really buzzing. We had comments like: `I’m going to stop wasting time;’ `I’m going to look to the future;’ `I’m going to be more goal-oriented;’ `I will start working - today!’ And these weren’t the top bunch - they were out on another trip.”

Now Mrs Davidson has to assess whether these promises bear fruit in the long term. But the speakers’ lives are testament to the fact that change is always possible. Mr McCann’s journey towards self-worth started when he realised he didn’t want his sister to kill herself, while Mr Warren gave up a pound;100,000 job in catering and radically reassessed his life when his marriage collapsed.

“Getting divorced left me feeling depressed . I was in a very dark place, left on my own, and I knew I had to change,” he says. “I found out that the biggest thing I really wanted to do was something that was life- changing for other people.”

It is difficult to measure, but he has a host of satisfied schools who feel he’s done that.

• www.richardmccann.co.uk; www.thebigpicture.eu.com.