The NHS is experiencing an “avalanche of need” over autism and attention deficit hyperactivity disorder (ADHD), but the system in place to cope with surging demand for assessments and treatments is “obsolete”, a health thinktank has warned. There must be a “radical rethink” of how people with the conditions are cared for in England if the health service is to meet the rapidly expanding need for services, according to the Nuffield Trust. The thinktank is calling for a “whole-system approach” across education, society and the NHS, amid changing social attitudes and better awareness of the conditions. It comes days after the NHS announced a major review of ADHD services. Thea Stein, the chief executive of the Nuffield Trust, said: “The extraordinary, unpredicted and unprecedented rise in demand for autism assessments and ADHD treatments have completely overtaken the NHS’s capacity to meet them. It is frankly impossible to imagine how the system can grow fast enough to fulfil this demand. “We shouldn’t underestimate what this means for children in particular: many schools expect an assessment and formal diagnosis to access support – and children and their families suffer while they wait.” Figures published by NHS Digital last month revealed that the number of patients waiting for an autism assessment in England was at its highest level since current data started in April 2019. Some 172,040 people were on waiting lists as of December 2023, up from 117,020 a year earlier and more than five times the 32,220 recorded in December 2019. Although the National Institute for Health and Care Excellence (Nice) recommends that people with suspected autism should be diagnosed within three months of a referral, statistics show 147,070 patients had been waiting for at least 13 weeks in December, more than six times the 24,250 in December 2019. New analysis of the data by the Nuffield Trust found that 79% of people who had been waiting 13 weeks or longer had not had their first appointment with a specialist, up from 44% in December 2019. Between October and December last year, those who had had their first appointment had waited an average of nine months since referral. In December 2019 the wait was an average of four months, the thinktank says. The Nuffield Trust also warned that the waiting times to be assessed for ADHD could be going unnoticed because of a lack of national published data. It said there had been a 51% rise in the number of people being prescribed medication for ADHD. The analysis showed a 28% increase in drugs prescribed to 10-14-year-olds, as well as a 146% jump among 30-34-year-olds. “We are only now beginning to recognise just how many people are neurodiverse,” Stein said. “The challenge is that we have an obsolete health service model in place to deal with this avalanche of need. The huge rise detailed in our analysis is likely to be down to a combination of changing social attitudes and better awareness. “We need to urgently understand the different elements of this complex picture and find a whole-system approach across education, society at large and the health service. Pumping more money into the current model certainly isn’t the solution: a radical rethink is required.” An NHS spokesperson said: “The NHS is fully committed to supporting and improving the lives of those with ADHD and autism, which is why we have published new national guidance to help local areas to manage the 50% increase in referrals they have seen over last year. “NHS England has also begun important work on investigating challenges in ADHD service provision and last month launched a cross-sector taskforce alongside government, to help provide a joined-up approach for the growing numbers of people coming forward for support.”