Children are waiting up to five years for an autism diagnosis assessment and up to four years following an ADHD referral, according to figures obtained by The Observer.

A Freedom of Information request revealed waiting times at 20 NHS Trusts, and while the average waiting time for an appointment following an autism referral was around six months, at some NHS Trusts, children are waiting years to be seen.

A postcode lottery of care

Of the 2,835 autistic children who were referred for an appointment at the Coventry and Warwickshire Trust Partnership NHS Trust, the average wait time was 88 weeks (around one-and-a-half years), while the longest waiting time was 251 weeks (nearly five years).

At the same Trust, 1,250 children with ADHD referrals are yet to have an appointment, having waited on average for 46 weeks, with the longest wait standing at 195 weeks (nearly four years).

Furthermore, there are around 2,800 children who are still awaiting their first appointment at Berkshire Healthcare NHS Trust, after waiting for more than a year (60 weeks) on average.

Children with ADHD referrals have waited even longer, for an average of 87 weeks for a first appointment, while the longest wait stands at nearly four years (193 weeks).

The huge variation in waiting times across the country reveals the stark reality of the postcode lottery of care, which has led to unequal access to treatment and support.

Delayed diagnoses can have a detrimental impact

A delayed autism or ADHD diagnosis can be extremely damaging in a myriad of ways. According to the BMA, a delayed autism diagnosis can impact on access to education, mental health and can result in increased financial costs.

It can also cause the individual and their family undue stress, as behaviour can be misinterpreted if they do not understand why they respond to certain factors in a specific way.

Waiting a long time for a diagnosis can also mean that other mental health conditions go unnoticed, this is particularly important as data suggests around 70% of autistic people have a co-occurring mental health condition.

A delayed ADHD diagnosis has similarly detrimental impacts, and can increase the risk of mental health problems including anxiety, depression and eating disorders.

Around 88,000 people in England are currently waiting for an autism diagnosis assessment

In response to the findings, the National Autistic Society (NAS) is urging the government to invest in additional diagnostic capacity and increase staff numbers to meet the rising referral levels.

Tim Nicholls, Head of Policy, Public Affairs and Research Partnerships at NAS, told Learning Disability Today: “A diagnosis can be lifechanging, it can help explain who you are and is vital to getting help. NICE guidance is clear: no one should wait longer than three months between being referred and first being seen.

"But without proper long-term funding for diagnosis services across the country, we’re worried people will still be waiting many months or even years for a diagnosis. For many, that means struggling without support at school, work or home. And new NHS figures suggest that 88,000 people in England are waiting for an autism diagnosis assessment. This is a huge number and, without intervention, will continue to increase.

"The Government must invest in rolling out these services, as set out in their five-year national autism strategy. For many thousands of autistic children, adults and families, progress can't come quickly enough."