ADHD is being missed in girls because they tend not be as badly behaved as boys, new NHS guidance suggests.
The National Institute of Health and Care Excellence (Nice) said girls and women are going undiagnosed because they were less likely to have “classic” symptoms of the disorder.
Around five per cent of school-age children are thought to suffer from ADHD - a condition which is commonly diagnosed as a result of restlessness and impulsive behaviour, often leading to disruption in the classroom.
Nice said girls tended to have symptoms which did not suggest hyperactivity - such as difficulties concentrating, forgetfulness and poor organisational skills - which were more likely to go un-noticed.
Dr Gillian Baird, professor of children's neurodisability at Guy's and St Thomas' NHS Foundation Trust and chairwoman of the Nice guideline committee, said that around half of all cases were likely to be going undiagnosed, with cases in girls more likely to be missed.
"Among the possibilities are that boys present with more obviously disruptive behaviour," she said.
The new guidance also calls on parents of children with ADHD not to put them on special diets, such as eliminating nuts, milk and wheat, or cut out artificial colours in a bid to improve behaviour.
Research funded by the Food Standards Agency (FSA) in 2002 also found that consuming some artificial food colourings and the preservative sodium benzoate could be linked to increased hyperactivity in some children.
But in the new guidance, Nice says doctors should not "advise elimination of artificial colouring and additives from the diet as a generally applicable treatment for children and young people with ADHD".
It said that parents who think there is a link between poor behaviour and diet should be advised to keep a diary, while a dietitian and mental health specialist should be involved before any restrictive diets - often known as “few food” diets are introduced.
Doctors should also not advise parents to routinely give their children fatty acid supplements, and parents should be told there is "no evidence about the long-term effectiveness or potential harms of a 'few food' diet for children with ADHD, and only limited evidence of short-term benefits".
The advice also suggests the drug ritalin should be routinely doled out to children diagnosed with ADHD- instead of saving it for a last resort when all else has failed.
The new guidance says medication such as ritalin should be offered to all children over the age of five if symptoms are having a “persistant significant impact” on their everyday life.
In the past decade, NHS prescriptions for the drug have more than doubled - with more than 1 million issued last year - even though drug treatment has not been indicated as a first-line treatment for children with ADHD.
Until now, Nice has said counselling or behavioural treatment should be tried first. The new advice says medication should be offered first, if “environmental modifications” - such as letting a child have breaks during lessons - have failed to have an impact.
But it says decisions to put children on medication should only be made after a visit to a specialist, contrasting with current advice which allows GPs to make a diagnosis.
The guidance follows a long controversy about the causes and treatment of ADHD. Last year 1.042m prescriptions were issued for drugs like ritalin, compared with 456,909 issued in 2006, NHS Digital figures show.
Source: The Telegraph