Disabled children's behaviour 'deteriorates at school'
The behaviour of children with disabilities and learning difficulties often worsens when they start school, research suggests.
The Millennium Cohort Study analysis suggests children with disabilities can become more hyperactive and have difficulty getting on with classmates.
It urges more stringent anti-bullying strategies in schools.
Disabled children can struggle on "multiple fronts" at school said co-author Prof Lucinda Platt.
The researchers from the Institute of Education, the London School of Economics and the National Children's Bureau, analysed information on some 6,371 children in England, born in 2000 and 2001, who are being followed by the Millennium Cohort Study.
They compared children without disabilities with children with a number of developmental, learning and health problems.
These included children with long-standing limiting illnesses such as asthma and those with special educational needs - such as hearing loss or learning difficulties.
The Millennium Cohort Study records information from parents on children's emotional, relationship and behavioural issues at the ages of three, five and seven.
The researchers were able to track the emergence of any problems and identify differences between the groups.
Children with long-standing illnesses and learning difficulties were more likely to display hyperactive behaviour, to have difficulties getting on with other children and to have emotional problems.
They found these traits often became become more pronounced between the ages of three and seven.
"Our findings suggest that some early school environments may exacerbate behavioural problems for disabled children in ways that cannot solely be solved by learning support - because the underlying issue is behavioural rather than cognitive," say the authors.
Prof Platt, of the London School of Economics Department of Social Policy, said: "School is not the easiest environment and if you have other things to struggle with it can be very difficult.
"Other children adjust and their behaviour improves - but this is often harder for children with other challenges", Prof Platt told BBC News.
The authors cite previous research which suggests children with disabilities and learning difficulties are more prone to being bullied.
They urge schools to adopt "more stringent anti-bullying strategies for those identified as different".
"If schools could be more aware that those with disabilities are likely to be struggling in multiple ways then they might be able to intervene earlier on," said Prof Platt.
Martha Evans of the Anti-Bullying Alliance said disabled children were too often seen as "other" and as being harder to empathise with by their schoolmates - which could lead to isolation and bullying.
She urged schools to do more to "celebrate what makes everyone different" and to develop a more inclusive attitude even when dealing with children whose behaviour "can be frustrating and difficult to deal with".
Neil Leitch, chief executive of the Pre-School Learning Alliance, said he would have liked the study to have included the impact of pre-school experiences on emotional and behavioural development as "the vast majority of three- and four-year-olds attend some kind of early years provision."
"It may be that schools should be looking to early years providers as examples of good practice."
Philippa Stobbs, assistant director of the Council for Disabled Children, said the findings "make it imperative that we focus on improving the learning environment for our youngest and most vulnerable children".