Spending on child disability benefits and support is poised to jump by £5bn over the next four years amid a surge in autism and ADHD diagnoses, new forecasts suggest. The Institute for Fiscal Studies (IFS) said that the cost of supporting children with special educational needs and disabilities (Send) will rise from £17bn to £22bn by 2029. Darcey Snape, research economist at IFS, said: “A clear risk is that the big increases in spending on children will be followed by higher spending on young adults. “An increasingly large share of young people are getting targeted educational and cash support to help them with special educational needs or disabilities. Average waiting times for an NHS assessment of autism now stand at over a year because of the rapid increase in referrals.