A team led by the University of Exeter Medical School analysed data from the Millennium Cohort Study, a database of more than 19,500 UK children born between 2000 and 2002.

Scientists have found evidence of a link between social and economic status and childhood attention deficit disorder (ADHD) in the UK.

A team led by the University of Exeter Medical School analysed data from the Millennium Cohort Study, a database of more than 19,500 UK children born between 2000 and 2002.

The study, published in the Journal of Child Psychology and Psychiatry, was funded by the Economic and Social Research Council's (ESRC) Secondary Data Analysis Initiative. The team also acknowledge funding from the National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care for the South West Peninsula (PenCLAHRC).

Findings showed that more children with ADHD came from families below the poverty line than the UK population as a whole, with average family incomes for households whose study child was affected by ADHD at £324 per week, compared to £391 for those whose child was not. The study found the odds of parents in social housing having a child with ADHD was roughly three times greater than for those who owned their own homes.

The team also found that the odds of younger mothers having a child with ADHD were significantly higher than for other mothers. Mothers with no qualifications were more than twice as likely to have a child with ADHD than those with degrees, and lone parents were more likely to have a child with ADHD diagnosis than households with two live-in parents.

Information was gathered from surveys when the cohort children were nine months old, and at the ages of three, five, seven and 11.

Dr Ginny Russell, of the University of Exeter Medical School, who led the study, said: "There is a genetic element to ADHD, but this study provides strong evidence that ADHD is also associated with a disadvantaged social and economic background.

"Some people believe that ADHD in children causes disadvantage to the economic situation of their family, but we found no evidence to support that theory. It's important to discover more about the causes of this disorder so that we can look towards prevention, and so that we can target treatment and support effectively."

The Millennium Cohort Study has been tracking more than 19,000 children in England, Scotland, Wales and Northern Ireland through their early childhood and plans to follow them into adulthood. It covers such diverse topics as parenting; childcare; school choice; child behaviour and cognitive development; child and parental health; parents' employment and education; income; housing; and neighbourhood. The Millennium Cohort Study was commissioned by the Economic and Social Research Council, whose funding has been supplemented by a consortium of government departments. It is managed by the Centre for Longitudinal Studies at the Institute of Education, University of London.

The findings support those of studies previously carried out in Northern Europe, the United States and Australia -- but the findings show that the link between ADHD and socioeconomic status exists in the UK.