By Caroline Parkinson
BBC News, health reporter
Derek thinks he is a lucky man.
Therapists say helping offenders communicate provides long-term benefits
Aged 20, he is serving a sentence for a violent offence in Polmont Young Offenders' Institution.
But he is getting help for the problem he believes was at the root of his offence - his communication difficulties.
"I speak very fast and people didn't really understand what I was saying. It caused conflict because I had to repeat things.
"It's caused me lots of problems, at school and with my family."
His therapist at Polmont, Jan Green, has helped Derek spot when he should make himself calmer to help him communicate.
"It's helped my confidence," he said. "And it's helped me get education."
Derek said he also hoped it would help him relate to his son when he is released from Polmont in a few years' time.
The institution is unique in having had speech and language therapy for the last 30 years.
'A relief to talk'
Ms Green says: "There are certain types of behaviour to watch out for. They may be people who are quite abrupt, who can't listen or who over-anticipate - or they may seem to be listening, but may be confused or unable to follow what's expected of them."
"What's surprising is that a lot of them say it's quite a relief to talk. Once I have started to ask them if certain things are a problem, they begin to open up."
Whatever the communication problem is, it will have been present throughout the young men's lives, so it isn't possible to provide a cure.
Around 2.5m people have a speech or language therapy
5% of children start school with problems
60% of young offenders have some form of speech, language or communication disorder
Therapists offer help people with communication, eating, drinking or swallowing problems
But they can be given ways of managing their problem.
They may be told to speak more slowly, and wait for someone to finish talking to them instead of jumping in so they don't have to deal with not understanding something.
Ms Green says such therapy can reduce offending rates because it addresses issues around comprehension and listening skills.
The young offenders can understand what they are being told by the courts or the police, and it helps them communicate their thoughts to others.
"For example, people with Asperger's syndrome might not understand why their offence is a crime, or how it's affected people they have offended against.
"We try to make people work through understanding what they've done, which might reduce the re-offending rates."
The Royal College of Speech and Language Therapists (RCSLT) says every young offender should have access to speech and language therapy.
There are currently just five therapists working with young offenders in the UK, but there are 22 young offenders institutions (YOIs) plus some dedicated young offenders wings in adult jails.
A young offender is someone in custody who is between 18 and 20, or 16 and 20 in Scotland.
A survey at Polmont in 2003 found 26% of young men had clinically significant communication problems and 70% of young offenders had literacy and numeracy problems.
This meant they could not benefit from educational classes, or therapies such as anger management, designed to help people on their release.
A national study carried out in 2001/02 showed re-offending rates were cut by up to 50% for people who were given targeted speech and language therapy.
Jane Mackenzie, England policy officer for the RCSLT, said: "Because speech and language therapists are trained to pinpoint the specific communication needs of young offenders, they are able to develop their language skills in a short space of time and dramatically reduce the risk of re-offending.
"Prison governors, officers and crucially, young offenders themselves, all agree that this targeted therapy can transform lives."
But a Home Office spokesman said young offenders' problems needed more complex and diverse solutions than putting a speech therapist into an institution, and that their stays were often too short to allow for meaningful help.
He said: "Often a young person's needs can be addressed through education, rather than by a speech and language therapist."
A new screening process for young offenders entering institutions, which in part will evaluate communication difficulties, is due to be introduced in October.