Thousands of pupils with dyslexia are being let down by a system that does not diagnose their other learning difficulties, a leading academic has claimed.
Dr Patricia Riddell, reader in psychology at Reading University, said schools would often label children as dyslexic but then not carry out further tests to discover whether they have problems such as attention deficit hyperactivity disorder (ADHD) and other syndromes.
An estimated one in 10 pupils have dyslexia or another reading disorder.
Dr Riddell has carried out research with colleague Dr Sue Cruddace which suggests that the overlap between speech and language disorders and dyslexia is about 50 per cent. In addition, about 25 per cent of dyslexic children also have an attention deficit disorder and about 25 per cent have a movement disorder.
She fears that thousands of pupils are being left behind academically because they are simply badged as dyslexic and not receiving the other help they need.
"I would challenge the idea that teachers would recognise every possible disorder," she said. "Children go through school having been told they are dyslexic and no one thought to find out if they are more than dyslexic, because there was no reason to.
"It is possible that a child that is playing up might be dyslexic, but it might not be picked up that it is an attention problem that is underlying the inability to read," Dr Riddell added.
Andrea Bilbow, chief executive officer of ADDISS, the ADHD charity agreed.
"(The problem is that) dyslexia is diagnosed by a psychologist, but ADHD is diagnosed by a psychiatrist. If a psychologist is not looking for ADHD, they are not going to find it.
"I have been rung up by 17 or 18-year-olds who have just been diagnosed with ADHD, who were seen by a psychologist at age 10 or 11 when they were told they had dyslexic tendencies," she added.
Beverley Walters, professional development manager of the special needs association Nasen, said: "There has been an increased interest in the overlap between difficulties such as ADHD and dyslexia in recent years. This would indicate the need for strategies that take account of all of the needs of the child, not just their most prevailing, to support their education."
The association has already held two conferences on co-occurring difficulties and both were oversubscribed.
Jo Fiddes, head of Five Lanes Primary School in Leeds, which has piloted dyslexia treatment, said: "Children can have a reading problem and then an underlying condition which comes to light later.
"There are certain things that, through experience, people will pick up in school and know which interventions work, but sometimes you need outside help. Then, when you refer children, you have to say which service you think you want."
Dr John Rack, head of research and professional development at Dyslexia Action and a member of the expert advisory group on Sir Jim Rose's review of dyslexia provision, said the issue was of growing concern.
The review found that to provide fully for children with dyslexic difficulties, it is important to make sure that efforts focus not only on tackling literacy, but take account of any co-occurring difficulties.
Dr Rack said: "The big question is not whether a child has dyslexia: yes or no? But do they have dyslexia, to what degree and are there co-occurring difficulties? There is a danger of simplistic use of labelling."
The Government has earmarked #163;10 million for dyslexia training, including 4,000 specialist teachers, following the review.
SOUTH FARNHAM JUNIOR: 'IT'S RARE FOR SEN CHILDREN TO HAVE ONE NEED'
"It is quite a compelling argument, to find a solution and move on," said Andrew Carter, head of South Farnham Junior School in Surrey.
All 134 pupils taking the key stage 2 tests at South Farnham in 2009 - about 13 per cent of whom have special educational needs - reached level 4 in English and maths.
Mr Carter said the key to identifying problems was frequent reviews and an ability to admit you may not have all the answers.
He added: "We do have children who have ADHD and also dyslexia. It's rare in my experience that children with special educational needs have one need. We certainly try and cover all aspects.
"If a child is showing behaviour difficulties sometimes people may say they are behaving in that way because they can't read, they can't read because they are dyslexic. So dyslexia is the problem.
"But if, six months later, you have some intensive programme and see some improvement in reading, but behaviour is still hopeless, then there is something else at play.
"Schools have to have a robust system to make sure they are looking across a child's development and they are reassessed at least twice a year."
NOT ONLY BUT ALSO: DYSLEXIA PLUS ...
Overlap between speech and language disorders and dyslexia 50%
Dyslexic children who also have an attention deficit disorder 25%
Dyslexic children who also have a movement disorder 25%.