Up to 60% of teenagers in young offenders institutions could be suffering from a behavioural disorder, it is claimed.
Experts say young offenders should have health checks
A leading paediatrician says the adolescents could have Attention Deficit Hyperactivity Disorder (ADHD).
Although other experts disagree the figure could be so high, the Youth Justice Board is to investigate the problem.
Dr Geoffrey Kewley, a consultant paediatrician with the National Learning Assessment and Neurocare centre says his theory many young offenders have ADHD is based on his experiences working with teenagers, rather than research.
But he says 95% of cases can be treated.
Now experts are recommending all teenagers who go into young offenders institutions should have health checks to assess if they are suffering from ADHD.
Children with ADHD are easily distracted, agitated and impulsive. Their behaviour can be erratic and sometimes violent.
But it is a controversial explanation for young offenders' behaviour, with some police officers seeing it as a convenient excuse.
Paul Mortimer, 16, from North Shields was diagnosed with ADHD four years ago. He was given the drug Ritalin to control his condition.
But it made him tired and sleepy. When other children discovered he was taking it, he was picked on, and he refused to continue taking it.
He has been arrested nineteen times in the last few years for offences ranging from vandalism to harassment and handling stolen goods.
He is currently the subject of a two year antisocial behaviour order, an electronic curfew, and could be given a custodial sentence if he offends again.
Chief Inspector Derek Scott from Northumbria Police told BBC Radio 5 Live: "I think the issue with Paul is that he obviously realises he is doing wrong.
"The ADHD is something which has given him mitigation at court.
"He's really got to look at his pattern of offending. He knows why he's been arrested. It's because of his general conduct and behaviour and complaints from people in the area.
"He needs to tackle that himself. His mother has supported his attempts to change his behaviour.
"Maybe he needs some other professional help from outside the criminal justice system, which might be something worth investigating."
Paul has not been to school for two years, since being expelled.
He spends his days roaming the streets - and admits he gets into trouble.
Paul said he gets into trouble because people tell him to do things and say they will hit him if he refuses.
He said he was bullied, and he's worried about what will happen to him
"I could get sent down. I don't go to school. I just go round to my mates and sit around, ride my bike."
"I'm very bored. I want to do things instead of sitting around."
Sir David Ramsbottom, former Chief Inspector of Prisons said he believed ADHD was a significant problem.
"It is a deficit in the bringing up of children. It shows a measure of social neglect in their development, and its one of the things that manifests when you see young offenders."
Sir David suggested early signs of the social and educational problems could be seen before a child was five.
"If they haven't been able to concentrate enough to be able to start reading and writing, they get further behind and they then leave school
"All people coming in to young offenders institution ought to be assessed for the whole variety of things that could be wrong with them."
He said a speech and language therapist visiting one institution had estimated 50% were suffering from cannabis-induced memory loss.
And up to 80% are estimated to be suffering from some kind of personality disorder.
"Attention deficit might be a symptom, it might be a cause - we don't know. But I'm all for the research being done."
"The time in young offenders institute offers an opportunity to challenge whatever it is and do something to raise their self esteem."