Two-thirds of Scotland's 32 local authorities reduced their ASN teachers between 2010 and 2014, according to figures published after a Parliamentary question by Labour MSP Siobhan McMahon. Overall, the total fell from 3,363 to 2,963, with cuts of up to a third in Aberdeenshire, the Highlands and Western Isles.
The Scottish Children's Services Coalition (SCSC), which supports children with complex needs and their carers, says one in five of the school population – 140,524 pupils – are identified as having ASN, of whom 62 per cent are boys. These include autism spectrum disorder (ASD), attention deficit/hyperactivity disorder (ADHD), and dyslexia.
"The fact that the number of additional support for learning teachers has reduced by 12 per cent since 2010 is deeply disturbing, especially as we know the great benefits to be gained through early detection and intervention," an SCSC spokesman said.
"Cutting numbers of these specialist staff will only serve to isolate more young people and their families. For us, this is completely unacceptable."
It would prevent many people from achieving further education or employment, he added. "If we are to close the attainment gap this is one group of individuals we need to devote resources to."
Cuts in support to educational psychologists, speech therapists and support staff were compounding the problem, he said. The coalition has previously expressed concern that the level of cuts could breach ASN pupils' statutory rights.
Ms McMahon said: "These figures are extremely worrying and highlight yet further failings in our education system by this SNP government. Only two days ago, first minister Nicola Sturgeon asked us to judge her on her government's education record, which, since 2007, has been a failure.
"These figures will only increase pressure on those dealing with pupils with ASN and further widen the educational attainment gap."
However, the Scottish government and local authorities said the reality was different because of the wider policy of inclusion in mainstream schools rather than special ones.
Pupils with additional support needs have been gaining better qualifications at school and going into more positive destinations afterwards every year since 2009/10, a government spokeswoman said.
The figures only represent the number of teachers who have additional support for learning as their main subject, she said.
"In 2014, 95 per cent of children and young people with additional support needs are recorded as learning within a mainstream school and receive support from a wide range of teaching staff across a range of subjects."
Stephanie Primrose, education spokeswoman for local authority body Cosla, said "sweeping conclusions" from the statistics should be resisted and mainstream education was a "team responsibility" that included teachers without a speciality in additional support needs.